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Amendment IV (the Fourth Amendment) to the United States Constitution is one of the provisions included in the Bill of Rights. The Amendment guards against unreasonable searches and seizures, and was originally designed as a response to the controversial writs of assistance (a type of general search warrant), which were a significant factor behind the American Revolution. Toward that end, the amendment specifies that judicially sanctioned search and arrest warrants must be supported by probable cause and be limited in scope according to specific information supplied by a person (usually a peace officer) who has sworn by it and is therefore accountable to the issuing court.

The amendment applies only to governmental actors; it does not guarantee to people the right to be free from unreasonable searches and seizures conducted by private citizens or organizations. The Bill of Rights only restricts the power of the federal government, but the Supreme Court of the United States has ruled that the Fourth Amendment is applicable to state governments by operation of the Fourteenth Amendment. The Supreme Court has said that some searches and seizures may violate the Fourth Amendment's reasonableness requirement even if a warrant is supported by probable cause and is limited in scope. Conversely, the Court has approved routine warrantless seizures, for example "where there is probable cause to believe that a criminal offense has been or is being committed."

Contents 1 Text 2 Precedent 2.1 British law 2.2 Colonial America 3 Amendment 4 Case law 4.1 Searches 4.1.1 Reasonable expectation of privacy 4.1.2 Probable cause to search 4.1.3 "Terry Frisk" 4.2 Seizures 4.3 Arrests 4.3.1 Citizen's arrest 4.3.2 Probable cause to arrest 4.3.3 Investigatory detentions, "Terry Stops" 4.4 Warrant requirement 5 Exclusionary rule 5.1 Exceptions to the exclusionary rule 6 Exceptions to the warrant requirement 6.1 Plain view doctrine 6.2 Open fields doctrine 6.2.1 Distinguishing open fields from curtilage 6.3 Exigent circumstances 6.4 Motor vehicle exception 6.5 Searches incident to a lawful arrest 6.6 Border Search Exception 6.7 Miscellaneous exceptions 7 The Internet, computers, and privacy in relation to the Fourth Amendment 7.1 Private employees and workplace computers 8 Important cases 9 Notes 10 References 11 External links

“

The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.

”

As with many other forms of American law, the fourth amendment finds its roots in British legal theory. Concepts found in the Magna Carta, as well as the concept of, "a man's house is his castle" is something that has long been a part of British theory. While the second was often without historical foundation, it nonetheless was an ideal that was held by subjects and legal theorists of the time. The first person to link these ideas of freedom and legal theory together was Robert Beale, who was clerk of the Privy Council in 1589. In a statement concerning Chapter 39 of the Magna Carta, he asked when agents of a prerogative court, acting under its warrant, could "enter into mens houses, break of[f] their chests and chambers" and carry off as evidence whatever they pleased. This was a milestone in history, as it brought into light that the Magna Carta was not just something to protect barons, but everyone. It subjected even royal officers to the notion that every subjects property was of equal protection under the great charter.

In the following century, Sir Edward Coke was a pioneer to what would become the fourth amendment. In his, "Institutes of the Laws of England", he asserted that a legal writ authorizing a legitimate search must be specific as to persons and places. He believed that Magna Carta outlawed general warrants based on mere surmise. In 1634, Coke's life was met with much irony as when as he lay dying the Privy Council's agents searched his home and law office for no specific items. In the raid, "seditious" papers were seized, along with manuscripts of his voluminous legal writings, as well as his personal valuables and personal letters (even one noted as being addressed to his children).^[1]

Sir Matthew Hale (a seventeenth-century legal theorist), addressed the issue of specific warrants in his book, "History of Pleas of the Crown". He criticized general warrants that failed to be specific in naming persons sought and/or the places to be searched. Hale was an early visionary regarding the concept of "probable cause" by maintaining that the person seeking a warrant should be examined judicially under oath so that a magistrate could determine whether there was sufficient grounds for an issuance. Furthermore, Hale was revolutionary in the idea that if an officer made an illegal search and arrest, that the officer would be liable to a civil suit for "false arrest". The concept of facing a civil suit for false arrest is a far cry to many current provisions that offer officers protection such as the "In good faith" ideal. An eighteenth-century collection of 108 warrants authorized by secretaries of state or by the King's Bench for the period of 1700-1763 shows that all but two of them were general warrants.^[2]

In 1762, John Wilkes, a member of the British parliament, anonymously published pamphlets that criticized the King's speech and a cider tax that was imposed. A general warrant (unspecific as to persons or places to be searched) was issued, to find the person responsible for the pamphlets. Authorities arrested 49 people in three days and finally arrested the actual printer of the pamphlets, who told authorities that Wilkes was responsible. Wilkes was arrested and all of his private papers seized. He was released days later, under privilege as a member of parliament. But, a suit was brought by the printers against the messengers, for the imprisonment of Wilkes. In the case, Huckle v. Money, Chief Justice Charles Pratt ruled that the general warrant was illegal. Another suit was brought against the undersecretary who issued the warrant. In Wilkes v. Wood, the Chief Justice again ruled in the favor of Wilkes.^[3]

In colonial America (eighteenth-century), legislation on search and seizure either copied British law or derived from it. Until 1750, all handbooks for justices of the peace, who issued warrants, contained or described only general warrants. William Cuddihy mentioned that a "colonial epidemic of general searches" existed. Until the 1760's, Cuddihy remarked that a "man's house was even less of a legal castle in America than in England" because when adopting British models the exceptions they had were ignored. As a result, an officer conducting a search in America was given every discretion. In a final remark by Cuddihy, it is said that, "Reasonable search and seizure in colonial America closely approximated whatever the searcher thought reasonable".

In 1756, the province of Massachusetts enacted legislation that abandoned the use of general warrants. This would stand to be the first law of its kind in American law. It was largely created due to a great public outcry against an an excise act of 1754 which authorized tax collectors to interrogate any subject, under oath, on the amount of rum, wine, and other spirits consumed in his premises in the past year (they taxed the spirits by the gallon). More importantly, this provincial impost law was enforced with general warrants to allow officers to search the wine cellars, chests and premises of any person's home. For customs officials, a writ of assistance (without an affidavit) allowed them to search for untaxed imported goods.^[4]

In February 1761, six months after King George II died, all writs of assistance expired. A group of merchants, represented by James Otis, petitioned the court to have hearings on the issue. In the hearing, Otis strongly denounced English policy towards the colonies and the use of general warrants and writs of assistance. But the court ruled against Otis.^[5] With overwhelming popularity, he was elected to the Massachusetts General Assembly, which passed legislation that only permitted special writs of assistance "granted by any judge or justice of the peace upon information under oath by any officer of the customs" and barred all other writs. The governor overturned the legislation, which he found contrary to British law.^[6] John Adams, who was present in the courtroom when Otis spoke, viewed these events in 1761 "as the spark in which originated the American Revolution."^[7]

The Virginia Declaration of Rights in 1776 included a prohibition on general warrants. This clause, drawn up at the Virginia Convention, was an important step towards requiring specific warrants, served as a precedent for the Fourth Amendment of the United States Constitution.^[8]

“

That general warrants, whereby any officer or messenger may be commanded to search suspected places without evidence of a fact committed, or to seize any person or persons not named, or whose offense is not particularly described and supported by evidence, are grievous and oppressive and ought not to be granted.[9]

”

Pennsylvania followed suit, including a provision its Declaration of Rights that specified the circumstances in which search and seizure could take place. Other states also included such provisions in their Declaration of Rights.^[10]

The Fourth Amendment to the United States Constitution requires that searches and seizures conducted under government authority be "reasonable". Toward that end, the amendment specifies that judicially sanctioned search and arrest warrants must be supported by probable cause and be limited in scope according to specific information supplied by a person (usually a peace officer) who has sworn by it and is therefore accountable to the issuing court.

The amendment applies only to governmental actors; it does not guarantee to people the right to be free from unreasonable searches and seizures conducted by private citizens or organizations.^[11] More specifically, the Bill of Rights only restricts the power of the federal government, but the Supreme Court of the United States has ruled that the Fourth Amendment is applicable to state governments by operation of the Fourteenth Amendment.^[12] Moreover, all state constitutions contain an analogous provision. For an example, see Article 1, § 7 of the Tennessee Constitution.

The Supreme Court has said that some searches and seizures may violate the Fourth Amendment's reasonableness requirement even if a warrant is supported by probable cause and is limited in scope.^[13] Conversely, the Court has approved routine warrantless seizures, for example "where there is probable cause to believe that a criminal offense has been or is being committed."^[14] Thus, the reasonableness requirement and the warrant requirement are somewhat different.

Regarding the Fourth Amendment's reasonableness requirement, it applies not just to a search in combination with a seizure, but also applies to a search without a seizure, as well as to a seizure without a search.^[15] Hence, the amendment is not limited to protecting elements of privacy or personal autonomy, but rather applies pervasively to virtually all aspects of criminal law. Nevertheless, the amendment is not so broad as to replace other constitutional provisions, such as replacing the Eighth Amendment's ban on "cruel and unusual" punishment with a more sweeping ban on "unreasonable" punishment.

The Fourth Amendment was needed because the writs of assistance had alarmed the colonies, and had inspired citizens to demand their rights. Congress recognized those demands, and so the Fourth Amendment stands today. But does the word "unreasonable" mean unreasonable according to the people of 1789, or according to people today, or according to judges, or according to juries? This question has not been definitively answered. However, to the extent that the Fourth Amendment is used for purposes of striking down statutes, the framers expected that the standard of review would be clear and irreconcilable variance with the Fourth Amendment.

The Fourth Amendment applies only to criminal law and not civil law. This was affirmed by the Supreme Court in 1855, in the Murray v. Hoboken Land decision.^[16] The jurisdiction of the Federal government in the realm of criminal law was narrow, up until the late nineteenth century when the Interstate Commerce Act and Sherman Antitrust Act were passed. As criminal jurisdiction of the Federal government expanded to include other areas such as narcotics, more questions about the Fourth Amendment came to the Supreme Court.^[17]

Not all actions by which governmental authorities obtain information from or about a person constitute a search. Therefore, government action triggers the amendment's protections only when the information or evidence at issue was obtained through a "search" within the meaning of the amendment. If no search occurs, no warrant is required. In general, authorities have searched when they have impeded upon a person's reasonable expectation of privacy.

In Katz v. United States,^[18] Justice Harlan issued a concurring opinion articulating the two-part test later adopted by the Court as the definition of a search for Fourth Amendment purposes: (1) governmental action must contravene an individual's actual, subjective expectation of privacy; (2) and that expectation of privacy must be reasonable, in the sense that society in general would recognize it as such.

In order to meet the first part of the test, the person from whom the information was obtained must demonstrate that they, in fact, had an actual, subjective expectation that the evidence obtained would not be available to the public. In other words, the person asserting that a search was conducted must show that they kept the evidence in a manner designed to ensure its privacy.

The second part of the test is analyzed objectively: would society at large deem a person's expectation of privacy to be reasonable? If it is plain that a person did not keep the evidence at issue in a private place, then no search is required to uncover the evidence. For example, there is generally no search when police officers look through garbage because a reasonable person would not expect that items placed in the garbage would necessarily remain private.^[19] Similarly, there is no search where officers monitor what phone numbers an individual dials,^[20] although Congress has enacted laws which restrict such monitoring. The Supreme Court has also ruled that there is no objectively reasonable expectation of privacy (and thus no search) when officers hovering in a helicopter 400 feet above a suspect's house conduct surveillance.^[21]

The Supreme Court has ruled that privacy extends to contents sent through the postal mail, requiring a search warrant for mail to be opened.^[22][23]

When police do conduct a search, the amendment requires them to have probable cause to believe that the search will uncover criminal activity or contraband. In other words, they must have legally sufficient reasons to believe a search is necessary. The Supreme Court has stated that probable cause to search is a flexible, common-sense standard. It merely requires that the facts available to the officer would 'warrant a man of reasonable caution in the belief,'^[24] that specific items may be contraband or stolen property or useful as evidence of a crime; it does not demand any showing that such a belief be correct or more likely true than false. A 'practical, nontechnical' probability that incriminating evidence is involved is all that is required.^[25]

However, in certain circumstances, authorities are permitted to conduct a search on a level of suspicion less than probable cause. In Terry v. Ohio,^[26] the Supreme Court decided that when a policeman "observes unusual conduct" that leads him to reasonably believe "that criminal activity may be afoot" and that the suspicious person has a weapon and is presently dangerous to the policeman or others, he may conduct a "pat-down search" (or "frisk"), to determine whether the person is in fact carrying a weapon. To conduct a frisk, the policeman must be able to point to specific and articulable facts which, taken together with rational inferences from those facts, reasonably warrant his actions.^[26] A vague hunch will not do.

The amendment proscribes unreasonable seizures of private property as well as persons. A seizure of property occurs when there is some meaningful interference by the police with an individual's possessory interests in that property,^[27] such as when police officers take an item away from a person and keep it to use as evidence of a crime.

A seizure is not constituted by merely approaching the individual on the street or in another public place, and asking him if he is willing to answer some questions, or by asking him questions if he seems willing to listen, or by offering in evidence in a criminal prosecution his voluntary answers to such questions. The person approached, however, does not have to answer any questions under these circumstances; he can simply walk away.^[28] He may not be detained even momentarily without reasonable, objective grounds for doing so; and his refusal to listen or answer does not, without more, furnish those grounds.^[29]

A person is seized within the meaning of the Fourth Amendment only when by means of physical force or show of authority his freedom of movement is restrained, and in the circumstances surrounding the incident, a reasonable person would believe that he was not free to leave.^[29] If the police are questioning someone, and they remain free to disregard the questions and walk away, there has been no intrusion upon the person's liberty or privacy, and for Fourth Amendment purposes — there has been no seizure.^[29]

Of course, when a person is arrested and taken into police custody, they have been seized (i.e., a reasonable person who is handcuffed and placed in the back of a squad car would not think they were free to leave). A person subjected to a routine traffic stop on the other hand, has been seized, but is not "arrested" because traffic stops are a relatively brief encounter and are more analogous to a Terry stop (see below) than to a formal arrest.^[30]

As mentioned in the introduction, the Fourth Amendment does not apply to private citizens, so in the case of a citizen's arrest, the Fourth Amendment standards are not relevant. However, many states have passed laws that dictate the specific circumstances in which a private citizen may arrest another. Typically, a person can make a citizen's arrest when: (1) a misdemeanor amounting to a public nuisance is committed in the arresting citizen's presence; or (2) a felony has been committed, and the arresting citizen has reasonable cause to believe that the person arrested committed it.^[31]

Main article: Probable Cause

Under common law, a police officer could arrest an individual if that individual committed a misdemeanor in the officer's presence, or if the officer had probable cause to believe that the individual was committing a felony (i.e., probable cause to believe that someone had committed a misdemeanor does not justify an arrest; the police officer has to actually witness the misdemeanor.)^[30]

The probable cause required for an arrest is different than that required for a search. Police have probable cause to make an arrest when "the facts and circumstances within their knowledge and of which they had reasonably trustworthy information" would lead a prudent person to believe that the arrested person had committed or was committing a crime.^[32] Probable cause to arrest must exist before the arrest is made: evidence discovered after the arrest may not be retroactively used to justify the arrest.^[33]

Not all seizures of the person must be justified by the probable cause standard required for arrests. Certain seizures are justifiable under the Fourth Amendment if there is reasonable suspicion, supported by specific and articulable facts, that a person has committed or is about to commit a crime.^[26] Note that this circumstance is different than the non-seizure police questioning discussed above, in these situations, the person stopped is not free to leave. A "Terry Stop" must be temporary and questioning must be limited to the purpose of the stop (i.e., if the policeman stopped you because he had reasonable suspicion to believe that you were driving a stolen car, after confirming that it is not stolen, he cannot force you to answer questions about anything else, such as the possession of contraband.)^[34] In justifying the particular intrusion the police officer must be able to point to specific and articulable facts which, taken together with rational inferences from those facts, reasonably warrant the intrusion

Under the amendment, law enforcement must receive written permission from a court of law, or otherwise qualified magistrate, in order to lawfully search for and seize evidence while investigating criminal activity. A court grants permission by issuing a writ known as a warrant. A search or seizure is generally unreasonable, i.e., unconstitutional, if conducted without a valid warrant,^[35] and the police must obtain a warrant whenever practicable.^[36] Warrantless searches and seizures are not automatically considered to be unreasonable, unless one of the specifically established and well-delineated exceptions to the warrant requirement is applicable.^[37]

Main article: exclusionary rule

One way courts enforce the rights guaranteed by the amendment is with the exclusionary rule. The rule provides that evidence obtained through a violation of the Fourth Amendment is generally not admissible by the prosecution during the defendant's criminal trial.

Before the Court adopted the exclusionary rule in Weeks v. United States, 232 U.S. 383 (1914), all evidence, no matter how seized, could be admitted in court, although the exclusionary rule existed to some extent prior to the Weeks decision. In Silverthorne Lumber Co. v. United States, 251 U.S. 385 (1920) and Nardone v. United States, 308 U.S. 338 (1939), the Court ruled that tips resulting from illegally obtained evidence is also inadmissible in trials as fruit of the poisonous tree; however, it wasn't until the Weeks decision that illegally obtained evidence was also excluded. The rule serves primarily to deter police officers from willfully violating a suspect's Fourth Amendment rights. The rationale behind the exclusionary rule is that if the police know evidence obtained in violation of the Fourth Amendment cannot be used to convict someone of a crime, they will not violate it. In delivering the opinion of the Court, Justice Frankfurter, in Wolf v. Colorado, 338 U.S. 25 (1949), rejected incorporation of the Fourth Amendment by dint of the Fourteenth Amendment. Later, in Mapp v. Ohio, 367 U.S. 643 (1961), the Supreme Court explicitly made the exclusionary rule applicable in state proceedings as an essential part of criminal procedure and basic human right.

As with most legal rules, there are a number of exceptions. In United States v. Leon, 468 U.S. 897 (1984), the Supreme Court applied the "good faith" rule and held that evidence seized by officers objectively and in good faith relying on a warrant later found to be defective was still admissible. The evidence would still be excluded if an officer dishonestly or recklessly prepares an affidavit forming the basis at the warrant, if the issuing magistrate abandons his neutrality, or if the warrant lacks sufficient particularity. The Leon case applies only to search warrants. It remains unclear whether the "good faith" exception applies to warrantless seizures in other contexts. On January 8, 1974, the Supreme Court ruled that grand juries may use allegedly illegally obtained evidence in questioning witnesses because, to hold otherwise, would interfere with grand jury independence and the place to contest the illegal search is after the accused is charged. United States v. Calandra, 414 U.S. 338.^[38]

The Supreme Court has held the rule does not apply in certain situations: (1) probation or parole revocation hearings; (2) tax hearings; (3) deportation hearings; (4) when government officials illegally seize evidence outside the United States; (5) when a "private actor" (i.e., not a governmental employee) illegally seized the evidence; or (6) when the illegally seized evidence is used to impeach the defendant's testimony. Furthermore, a defendant has standing to object to the admission of unconstitutionally seized evidence only if such seizure violated his own Fourth Amendment rights; a defendant may not assert the rights of a third party. For example, a mere passenger in a car has standing to contest the stop of the car and a search of his person, but he usually lacks standing to contest a search of the car. If he is a passenger in his own car, however, he would have standing to challenge the search of the car.

Closely related to the exclusionary rule is the "fruit of the poisonous tree" doctrine, under which the government is prohibited from introducing any evidence that was obtained subsequent to and as a result of the illegal search.

In any event, whether a search or seizure is "unreasonable", and therefore unconstitutional, can entail complex analysis of common law precedent and the facts of the case. Additionally, as searches and seizures are distinct activities, the constitutionality of a search is analyzed differently than a seizure.

Courts have developed a number of exceptions to the warrant requirement:

Main article: Plain view doctrine

If an officer is lawfully present, they may search and seize objects that are in "plain view". Before the seizure, however, the officers must have probable cause to believe that the objects are contraband.

Main article: Open fields doctrine

Similarly, "open fields"—pastures, open water, woods and other such areas—may be searched without a warrant, on the basis that the individuals conducting activities therein had no reasonable expectations of privacy. Contrary to its apparent meaning, the "open fields" doctrine has been expanded to include almost any open space other than the land immediately surrounding a domicile. For instance, in Oliver v. United States 466 U.S. 170 (1984), the police ignored a "no trespassing" sign, trespassed onto the suspect's land without a warrant, followed a path several hundred yards, and discovered a field of marijuana. The Supreme Court ruled that no search had taken place.

The open fields doctrine was first articulated by the U.S. Supreme Court in Hester v. United States,^[39] which stated that “the special protection accorded by the Fourth Amendment to the people in their ‘persons, houses, papers, and effects,’ is not extended to the open fields."^[40] This opinion appears to be decided on the basis that "open fields are not a 'constitutionally protected area' because they cannot be construed as "persons, houses, papers, [or] effects."

This method of reasoning gave way with the arrival of the landmark case^[18] which established a two-part test for what constitutes a search within the meaning of the Fourth Amendment. The relevant criteria are "first that a person have exhibited an actual (subjective) expectation of privacy and, second, that the expectation be one that society is prepared to recognize as reasonable."^[18] Under this “new” analysis of the Fourth Amendment, privacy expectations deemed unreasonable by society cannot be validated by any steps taken by the defendant to shield the area from view.

In Oliver v. United States,^[41] the Supreme Court held that a privacy expectation regarding an open field is unreasonable:

…open fields do not provide the setting for those intimate activities that the Amendment is intended to shelter from government interference or surveillance. There is no societal interest in protecting the privacy of those activities, such as the cultivation of crops, that occur in open fields.^[42]

While open fields are not protected by the Fourth Amendment, the curtilage, or outdoor area immediately surrounding the home, is. Courts have treated this area as an extension of the house and as such subject to all the privacy protections afforded a person’s home (unlike a person's open fields) under the Fourth Amendment.

An area is curtilage if it "harbors the intimate activity associated with the sanctity of a man's home and the privacies of life."^[43] Courts make this determination by examining "whether the area is included within an enclosure surrounding the home, the nature of the uses to which the area is put, and the steps taken by the resident to protect the area from observation by people passing by."^[44] Theoretically, many structures might extend the curtilage protection to the areas immediately surrounding them. The courts have gone so far as to treat a tent as a home for Fourth Amendment purposes in the past.^[45][46][47] It is possible that the area immediately surrounding a tent (or any structure used as a home) might be considered curtilage.

Despite this rather broad interpretation of curtilage, the courts seem willing to find areas to be outside of the curtilage if they are in any way separate from the home (by a fence, great distance, other structures, even certain plants).^[48]

There are also "exigent circumstances" exceptions to the warrant requirement. For instance, if an officer reasonably believes that a suspect may destroy evidence, he might be permitted to seize the evidence without a warrant. If an officer reasonably perceives an immediate deadly or physical threat to his life or the lives of others, the exigent circumstances exception applies.

Main article: Motor vehicle exception

The Supreme Court has also held that individuals in automobiles have a reduced expectation of privacy, because vehicles generally do not serve as residences or repositories of personal effects. Vehicles may not be randomly stopped and searched; there must be probable cause or reasonable suspicion of criminal activity. Items in "plain view" may be seized; areas that could potentially hide weapons may also be searched. With probable cause, police officers may search any area in the vehicle. They may not, however, extend the search to the vehicle's passengers without probable cause to search those passengers.

Main article: Searches incident to a lawful arrest

Another common law rule—that permitting searches incident to an arrest without warrant—has been applied in American law. The justification for such a search is that the arrested individual must be prevented from destroying evidence or using a weapon against the arresting officer. In Trupiano v. United States, 334 U.S. 699 (1948), the Supreme Court held that "a search or seizure without a warrant as an incident to a lawful arrest has always been considered to be a strictly limited right. It grows out of the inherent necessities of the situation at the time of the arrest. But there must be something more in the way of necessity than merely a lawful arrest." In United States v. Rabinowitz, 339 U.S. 56 (1950), the Court reversed its previous ruling, holding that the officers' opportunity to obtain a warrant was not germane to the reasonableness of a search incident to an arrest. The decision suggested that any area within the "immediate control" of the arrestee could be searched, but it did not define the term. In deciding Chimel v. California, 395 U.S. 752 (1969), the Supreme Court elucidated its previous decisions. It held that when an arrest is made, it is reasonable for the officer to search the arrestee for weapons and evidence.

Similarly, it was held that it is reasonable for the officer to search the area within the arrestee's immediate control, that is, the area from which the defendant may gain access to a weapon or evidence. A search of the room in which the arrest is made is therefore permissible, but the same is not true of a search of other rooms, as the arrestee would not probably be able to access weapons or evidence in those rooms at the time of arrest.

Main article: Border search exception

Searches conducted at the United States border or the equivalent of the border (such as an international airport) may be conducted without a warrant or probable cause subject to the "border-search" exception. see United States v. Flores-Montano, 541 U.S. 149 (2004)); United States v. Montoya de Hernandez, 473 U.S. 531 (1985); United States v. Ramsey, 431 U.S. 606 (1977). Most border searches may be conducted entirely at random, without any level of suspicion, pursuant to Customs' plenary search authority. However, searches that intrude upon traveler's personal dignity and privacy interests, including strip and body cavity searches must be supported by 'reasonable suspicion.' See Flores-Montano, 541 U.S. at 152-53. One issue currently pending before federal courts is whether the search of the information on a traveler's electronic materials, including personal files on a laptop computer, may be searched at random, without suspicion. See United States v. Ickes, 393 F.3d 501(4th Cir. 2005); United States v. Arnold, 454 F. Supp. 2d 999, 1003-04 (N.D. Cal. 2006), appeal docketed, No. 06-50581 (9th Cir. June 13, 2007).

It has been held that searches in public schools do not require warrants, however there has to be reasonable belief. (See New Jersey v. T. L. O., 468 U.S. 325 (1985)). It is merely necessary that the searching officers have reasonable grounds for believing that the search will result in the finding of evidence of illegal activity.

Similarly, government offices may be searched for evidence of work-related misconduct by government employees on similar grounds. Searches of prison cells are subject to no restraints relating to reasonableness or probable cause or searches undertaken as a condition of parole (see Samson v. California, 546 U.S. __ (2006).

Finally, a search is reasonable if the target without coercion consents to the search, even if the target is unaware and not told about their right to refuse to cooperate.

In the last decade courts have had to determine whether law enforcement officials can access evidence of illegal activity stored on digital technology without encroaching on a person's Fourth Amendment rights.

Many cases discuss whether a private employee (i.e., not a government employee) who stores incriminating evidence in workplace computers is protected by the Fourth Amendment's reasonable expectation of privacy standard in a criminal proceeding. However, these cases do not appear to produce a uniform and consistent standard of law.

Most case law holds that employees do not have a reasonable expectation of privacy when it comes to their work related electronic communications. See, e.g. US v. Simons, 206 F.3d 392, 398 (4th Cir., Feb. 28, 2000).

However, one federal court held that employees can assert the attorney-client privilege with respect to certain communications on company laptops. See Curto v. Medical World Comm., No. 03CV6327, 2006 U.S. Dist. LEXIS 29387 (E.D.N.Y. May 15, 2006).

Another recent federal case discussed this topic. On January 30, 2007, the Ninth Circuit court in US v. Ziegler, reversed its earlier August 2006 decision upon a petition for rehearing. In contrast to the earlier decision, the Court acknowledged that an employee has a right to privacy in his workplace computer. However, the Court also found that an employer can consent to any illegal searches and seizures. See US v. Ziegler, ___F.3d 1077 (9th Cir. Jan. 30, 2007, No. 05-30177). [1] Cf. US v. Ziegler, 456 F.3d 1138 (9th Cir. 2006).

In Ziegler, an employee had accessed child pornography websites from his workplace. His employer noticed his activities, made copies of the hard drive, and gave the FBI the employee's computer. At his criminal trial, Ziegler filed a motion to suppress the evidence because he argued that the government violated his Fourth Amendment rights.

The Ninth Circuit allowed the lower court to admit the child pornography evidence. After reviewing relevant Supreme Court opinions on a reasonable expectation of privacy, the Court acknowledged that Ziegler had a reasonable expectation of privacy at his office and on his computer. That Court also found that his employer could consent to a government search of the computer, and that did not violate Ziegler's Fourth Amendment rights.

A New Jersey appellate court has also issued an opinion on the privacy rights of computer users. That court held that computer users can expect that the personal information they give their internet service providers are considered private. State v. Reid 2007 N.J. Super. LEXIS 11 (January 22, 2007). [2].

In that case, prosecutors asserted that Shirley Reid broke into her employer’s computer system and changed its shipping address and password for suppliers. The police discovered her identity after getting a subpoena to the internet provider, Comcast Internet Service.

The lower court suppressed information from the internet service provider that linked Reid with the crime. The New Jersey appellate court agreed with this decision. Although this case does not directly discuss the Fourth amendment, it illustrates that some states are providing more privacy protection to computer users than the federal courts. It also illustrates that case law on privacy in workplace computers is still evolving.

Exclusionary Rule

• Weeks v. United States, 232 U.S. 383 (1914)
• Wolf v. Colorado (1949)
• Mapp v. Ohio, 367 U.S. 643 (1961)
• United States v. Leon (1984)
• Pennsylvania Board of Probation and Parole v. Scott (1998)

Privacy

• Olmstead v. United States (1928)
• Katz v. United States (1967)
• Zurcher v. Stanford Daily (1978)
• United States v. Karo (1984)
• California v. Greenwood (1988)
• Florida v. Riley (1989)
• Kyllo v. United States (2001)
• United States v. White (2003)
• Hudson v. Michigan (2006)

Probable Cause

• Spinelli v. United States (1969)
• Illinois v. Gates (1983)

Search Warrants

• Franks v. Delaware (1979)
• Maryland v. Garrison (1987)
• Richards v. Wisconsin (1997)
• Groh v. Ramirez (2004)

Arrest and Search of a Person Without a Warrant

• United States v. Watson (1976)
• United States v. Robinson (1973)
• Whren v. United States (1996)
• Atwater v. City of Lago Vista (2001)
• Tennessee v. Garner (1985)

Search of and Seizure from a Residence Without a Warrant

• Chimel v. California (1969)
• Vale v. Louisiana (1970)
• Payton v. New York (1980)
• Steagald v. United States (1981)
• Illinois v. McArthur (2001)

Search and Seizure of Vehicles and Containers Without a Warrant

• South Dakota v. Opperman (1976)
• United States v. Chadwick (1977)
• Arkansas v. Sanders (1979)
• New York v. Belton (1981)
• United States v. Ross (1982)
• California v. Carney (1985)
• Colorado v. Bertine (1987)
• California v. Acevedo (1991)
• Knowles v. Iowa, 525 U.S. 113 (1998)
• Wyoming v. Houghton (1999)

Stop and Frisk

• Terry v. Ohio (1968)
• Florida v. Royer (1983)
• Michigan v. Long (1983)
• United States v. Place (1983)
• Florida v. J.L. (2000)
• [[Illinois v. Wardlow (2000)
• United States v. Drayton (2002)
• Hiibel v. Sixth Judicial District Court of Nevada (2004)

Border Searches

• United States v. Montoya de Hernandez, 473 U.S. 531 (1985)
• United States v. Ramsey, 431 U.S. 606 (1977)
• United States v. Flores-Montano, 541 U.S. 149 (2004)
• United States v. Thirty-Seven Photographs, 402 U.S. 363(1971)

• Davies, Thomas Y. (1999). "Recovering the Original Fourth Amendment". Michigan Law Review 98: 547. 
• Kilman, Johnny and George Costello (Eds) (2000). The Constitution of the United States of America: Analysis and Interpretation. GPO.
• Lasson, Nelson B. (1937). The History and Development of the Fourth Amendment to the United States Constitution. Johns Hopkins Press. 
• Levy, Leonard Williams (1995). Seasoned Judgments: The American Constitution, Rights, and History. Transaction Publishers. 
• Ducat, Craig R. and Harold W. Chase (Eds) (1992). Constiutional Interpretation (5th Ed.). West Publishing Company, 797-818. 

• CRS Annotated Constitution: 4th Amendment, Cornell University

v • d • e United States Constitution
Text	(at Wikisource): Preamble and Articles · Bill of Rights · Subsequent Amendments
Formation	History · Articles of Confederation · Mount Vernon Conference · Annapolis Convention · Philadelphia Convention · New Jersey Plan · Virginia Plan · Connecticut Compromise · Three-fifths compromise · Signatories · Massachusetts Compromise · Federalist Papers (list)
Amendments	Bill of Rights · Ratified · Proposed · Unsuccessful · Conventions to propose · State ratifying conventions
Clauses	Appointments · Appropriations · Case or controversy · Citizenship · Commerce · Compact · Confrontation · Contract · Copyright and Patent · Due Process · Emolument · Equal Protection · Establishment · Exceptions · Ex post facto · Extradition · Free Exercise · Fugitive Slave · Full Faith and Credit · General Welfare · Guarantee · Impeachment · Militia · Natural–born citizen · Necessary and Proper · No Religious Test · Origination · Post Offices and Post Roads · Presentment · Privileges and Immunities (Art. IV) · Privileges or Immunities (14th Amend.) · Speech or Debate · Supremacy · Suspension · Takings Clause · Territorial · Trial by Jury · Three-fifths · Vesting · War Powers
Interpretation	Theory · Concurrent powers · Congressional enforcement · Double jeopardy · Dormant Commerce Clause · Enumerated powers · Executive privilege · Incorporation of the Bill of Rights · Nondelegation · Preamble · Preemption · Separation of church and state · Separation of powers