Amendment Four to the Constitution was ratified on December 15, 1791. It protects the American people from unreasonable searches and seizures. The official text is written as such:
“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.”
At the time of its creation, the Fourth Amendment was made in response to increasing infringements on privacy in both the colonies and in England. In England, “general warrants” authorized royal officials to pursue and search the belongings of a person without any cause other than the perceived suspicion that they were political enemies. Meanwhile in the colonies, “writs of assistance” authorized officials to track down and conduct warrantless searches for untaxed items. Both the “general warrants” and “writs of assistance” were challenged in court, but only the former was considered to be a violation of the law. A key element of the Fourth Amendment was that every search or seizure of an individual’s home and property was to be authorized by a judge beforehand, and that the entire operation had to be on the grounds of “probable cause.” This section of the Fourth Amendment was most prominently highlighted in a pair of 20th century Supreme Court decisions. 1920’s Silverthorne Lumber Co. v. United States determined that illegally seized and copied evidence was “tainted” and was therefore inadmissible in a legal trial. Nineteen years later, Nardone v. United States ruled that evidence that was obtained through warrantless wiretaps was inadmissible in court proceedings.
The historical context of the Fourth Amendment has been perceived as being a stark contrast from the modern world in which it has been invoked. For most countries in the late-18th and early-19th centuries – including the United States – policing was largely conducted by citizens during nighttime patrols, while elected sheriffs and constables were more likely found in formal leadership settings. As American cities grew larger in size and population, many of their respective leaders called for the creation of full-time police officers to maintain law and order. An example of this is the city of Boston, where up until the mid-19th century they had the old colonial night watch, and a Day Police consisting of only six officers. After the city government called for a more organized law enforcement body, the Boston Police Department was founded in 1854, making it the first and oldest municipal police force in the country.
The 20th and early-21st centuries have experienced a series of debates surrounding the longevity and future of the Fourth Amendment. During the Cold War, the federal government was involved in various programs that spied on the American public’s telephone calls, radio signals, and mail. In programs such as the FBI’s COINTELPRO and the CIA’s Operation CHAOS, not only were individuals considered to be “threats to national security” targeted, but also unrelated citizens who got caught up in the searches. The 9/11 terrorist attacks and the subsequent War on Terror led to another wave of mass surveillance, extending to citizens and their luggage on airplanes, automated drones, and the burgeoning field of global Internet communications. Relative to the Fourth Amendment, those who are more supportive of these measures have argued that they are rooted in the “probable cause” of deterring crime and terrorism. Conversely, critics of these programs argue that they are too widespread and invasive to be justified by the Fourth Amendment. Some have further argued that the bulk of the data retrieved from these large-scale programs are irrelevant to a potential court trial, was illegally obtained, or was an invasion of someone’s personal affairs. With all the major changes in politics, society, and technology that has emerged since the late-18th century, the Fourth Amendment has often found itself in the position of being a Constitutional element that has practically become common knowledge.
Written by Nicholas J. Dilley, Ronald Reagan Presidential Library & Museum