
The Fourth Amendment to the United States Constitution, also known as Amendment 4, deals with the right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures. This amendment was introduced in 1789 by James Madison, along with the other amendments in the Bill of Rights, and was ratified on December 15, 1791. The Fourth Amendment has been a topic of discussion and interpretation by the courts, with cases such as Carpenter v. United States (2018) and Katz v. United States (1967) shaping our understanding of its protections in the modern world. With the evolution of technology and society, the Fourth Amendment has often been at the centre of debates surrounding privacy and security.
| Characteristics | Values |
|---|---|
| Name | Fourth Amendment |
| Other Names | Amendment Four, The Right to Privacy |
| Date Passed by Congress | September 25, 1789 |
| Date Ratified | December 15, 1791 |
| Date Announced as Part of the Constitution | March 1, 1792 |
| Introduced By | James Madison |
| Purpose | To protect people's right to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures |
| Notable Court Cases | Carpenter v. United States (2018), Katz v. United States (1967), Silverthorne Lumber Co. v. United States (1920), Nardone v. United States (1939), Johnson v. United States (1948) |
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What You'll Learn

The right to privacy
The Fourth Amendment to the United States Constitution, also known as "The Right to Privacy", was introduced in Congress in 1789 and ratified on December 15, 1791. It states:
> "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."
This amendment was a response to Anti-Federalist objections to the new Constitution and sought to protect citizens from general warrants, whereby officers could search suspected places without evidence of a committed crime. It also added the requirement that all searches must be "reasonable" and served as a basis for the Fourth Amendment's language.
The Fourth Amendment has been invoked in modern times, particularly in the context of the War on Terror, with some arguing that mass surveillance programs are necessary to deter crime and terrorism. However, critics argue that these programs are too invasive and violate the Fourth Amendment.
The amendment has also been the subject of several court cases, including Carpenter v. United States (2018), which ruled that individuals have a reasonable expectation of privacy regarding their cell phone records, even if they have turned over this information to third parties. Another notable case is Katz v. United States (1967), where the Supreme Court held that the amendment's protections extend beyond physical locations to include intrusions on the privacy of individuals.
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Searches and seizures
The Fourth Amendment to the United States Constitution, also known as "The Right to Privacy", was introduced in Congress in 1789 by James Madison. It was ratified on December 15, 1791, and officially became part of the Constitution on March 1, 1792. The amendment states that:
> 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.
This amendment was introduced to address concerns about general warrants, which allowed officers or messengers to search suspected places without evidence of a committed crime, and to seize individuals not named or whose offences were not described and supported by evidence. The Fourth Amendment requires that all searches and seizures be authorised by a judge and conducted on the grounds of "probable cause".
The amendment's protections were initially limited to physical intrusions of property or persons, but in Katz v. United States (1967), the Supreme Court held that they extend to intrusions on the privacy of individuals as well. This means that a warrant is typically required for search and seizure activities, with some exceptions, such as consent searches, motor vehicle searches, evidence in plain view, exigent circumstances, and border searches.
The Fourth Amendment has been invoked in numerous cases, including Carpenter v. United States (2018), which ruled that individuals have a reasonable expectation of privacy regarding their cell phone records, even though they voluntarily provided this information to cell phone companies. Another notable case is State v. Malecha, where the exclusionary rule was applied, barring the use of evidence collected in an unconstitutional manner.
Despite the Fourth Amendment's protections, critics argue that modern mass surveillance programs, particularly in the post-9/11 era, are too invasive and widespread to be justified under the amendment. Additionally, there have been discussions about the role of race in Fourth Amendment search-and-seizure cases, with some arguing that it should be considered in these contexts.
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Probable cause
The Fourth Amendment to the United States Constitution, ratified on December 15, 1791, deals with the
> 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.
The Fourth Amendment was introduced in response to Anti-Federalist objections to the new Constitution, and to address the dangers presented by general warrants, which allowed officers to search suspected places without evidence of a committed crime.
The concept of "probable cause" is central to the meaning of the warrant clause. While the Fourth Amendment does not define "probable cause", it is generally understood to mean that an applicant for a warrant must present sufficient facts to enable a determination of probable cause. This determination is made by a magistrate or judicial officer, who decides whether there are "reasonable grounds" for the warrant.
In the context of arrests, probable cause exists when a police officer has a reasonable belief in the guilt of a suspect, based on the facts and information prior to the arrest. A warrantless arrest may be justified by probable cause and urgent need, such as when a suspect is a threat to public safety or about to escape.
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Violations of Fourth Amendment rights
The Fourth Amendment to the United States Constitution, also known as Amendment IV, is a part of the Bill of Rights. It was introduced in 1789 by James Madison and officially became part of the Constitution on March 1, 1792. The amendment protects the right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures. It also sets requirements for issuing warrants, stating that warrants must be issued by a judge or magistrate and justified by probable cause.
Despite these protections, violations of Fourth Amendment rights have occurred and continue to occur. One example is the FBI's COINTELPRO program, which in 1970 illegally exposed actress Jean Seberg's secret support for the Black Panther Party. In another instance, the Supreme Court held in Silverman v. United States (1961) that the Fourth Amendment's core is the right to be free from unreasonable governmental intrusion in one's home. However, with the advent of new technologies and the War on Terror following the 9/11 attacks, mass surveillance programs have emerged that some argue violate the Fourth Amendment. Critics claim that these programs are too invasive and widespread to be justified under the amendment.
Additionally, there have been legal disputes over what constitutes a "'search'" or "seizure" under the Fourth Amendment. Early court decisions limited the amendment's scope to physical intrusions of property or persons. However, in Katz v. United States (1967), the Supreme Court extended its protections to include intrusions on the privacy of individuals as well. This case established that a "'search'" under the Fourth Amendment occurs when there is an invasion of an individual's reasonable expectation of privacy by a government employee or agent.
To address violations of Fourth Amendment rights, individuals can file a Bivens action against federal law enforcement officials for damages resulting from an unlawful search and seizure. Courts have generally required claimants to prove that they had a justifiable expectation of privacy that was arbitrarily violated by the government. This was demonstrated in Carpenter v. United States (2018), where the Court ruled that individuals have a reasonable expectation of privacy under the Fourth Amendment regarding their cell phone records, even though they voluntarily provided this information to cell phone companies.
While the Fourth Amendment provides important protections against unreasonable searches and seizures, it is clear that violations of these rights have occurred and continue to be a subject of legal debate and enforcement.
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General warrants
The Fourth Amendment to the United States Constitution, also known as Amendment 4, was ratified on December 15, 1791. It protects the right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures. The amendment also states that no warrants shall be issued without probable cause, supported by an oath or affirmation, and particularly describing the place to be searched and the persons or things to be seized.
The Fourth Amendment requires that a warrant be obtained before conducting a search or seizure, with limited exceptions. These exceptions include consent searches, motor vehicle searches, evidence in plain view, exigent circumstances, and border searches. In general, warrantless searches of private premises are prohibited under the Fourth Amendment, unless a specific exception applies. For example, a warrantless search may be lawful if an officer has consent to search, if the search is incident to a lawful arrest, or if there are exigent circumstances, such as imminent danger or the destruction of evidence.
The amendment has been interpreted and applied in numerous court cases over the years, with the Supreme Court holding that its protections extend beyond physical intrusion of property or persons to include intrusions on the privacy of individuals. The amendment has also been invoked in modern times, with critics arguing that mass surveillance programs implemented after the 9/11 terrorist attacks violate the right to privacy protected by the Fourth Amendment.
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Frequently asked questions
The Fourth Amendment to the United States Constitution is the right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures.
This means that no warrants shall be issued without probable cause, supported by oath or affirmation, and describing the place to be searched, and the persons or things to be seized.
The Fourth Amendment was introduced in Congress in 1789 by James Madison, along with the other amendments in the Bill of Rights, in response to Anti-Federalist objections to the new Constitution. It was ratified on December 15, 1791.

























