The Fourth Amendment to the United States Constitution is part of the Bill of Rights. It prohibits unreasonable searches and seizures and sets requirements for issuing warrants: warrants must be issued by a judge or magistrate, justified by probable cause, supported by oath or affirmation, and must particularly describe the place to be searched and the persons or things to be seized.
Katz v. United States, 389 U.S. 347 (1967), was a landmark decision of the U.S. Supreme Court in which the Court redefined what constitutes a "search" or "seizure" with regard to the protections of the Fourth Amendment to the U.S. Constitution. The ruling expanded the Fourth Amendment's protections from an individual's "persons, houses, papers, and effects", as specified in the Constitution's text, to include any areas where a person has a "reasonable expectation of privacy". The reasonable expectation of privacy standard, known as the Katz test, was formulated in a concurring opinion by Justice John Marshall Harlan II.
In United States constitutional law, expectation of privacy is a legal test which is crucial in defining the scope of the applicability of the privacy protections of the Fourth Amendment to the U.S. Constitution. It is related to, but is not the same as, a right to privacy, a much broader concept which is found in many legal systems. Overall, expectations of privacy can be subjective or objective.
Smith v. Maryland, 442 U.S. 735 (1979), was a Supreme Court case holding that the installation and use of a pen register by the police to obtain information on a suspect's telephone calls was not a "search" within the meaning of the Fourth Amendment to the United States Constitution, and hence no search warrant was required. In the majority opinion, Justice Harry Blackmun rejected the idea that the installation and use of a pen register constitutes a violation of the suspect's reasonable expectation of privacy since the telephone numbers would be available to and recorded by the phone company anyway.
Ferguson v. City of Charleston, 532 U.S. 67 (2001), is a United States Supreme Court decision that found Medical University of South Carolina's policy regarding involuntary drug testing of pregnant women to violate the Fourth Amendment. The Court held that the search in question was unreasonable.
In United States criminal law, the border search exception is a doctrine that allows searches and seizures at international borders and their functional equivalent without a warrant or probable cause. Generally speaking, searches within 100 miles of the border are more permissible without a warrant than those conducted elsewhere in the U.S. The doctrine also allows federal agents to search people at border crossings without a warrant or probable cause. The government is allowed to use scanning devices and to search personal electronics. Invasive bodily searches, however, require reasonable suspicion.
United States v. Arnold, 533 F.3d 1003, is a United States court case in which the United States Court of Appeals for the Ninth Circuit held that the Fourth Amendment to the United States Constitution does not require government agents to have reasonable suspicion before searching laptops or other digital devices at the border, including international airports.
The Stored Communications Act is a law that addresses voluntary and compelled disclosure of "stored wire and electronic communications and transactional records" held by third-party Internet service providers (ISPs). It was enacted as Title II of the Electronic Communications Privacy Act of 1986 (ECPA).
Mancusi v. DeForte, 392 U.S. 364 (1968), is a decision of the United States Supreme Court on privacy and the Fourth Amendment. It originated in the lower courts as United States ex rel. Frank DeForte, appellant v. Vincent R. Mancusi, Warden of Attica Prison, Attica, New York, appellee, a petition for a writ of habeas corpus by a prisoner who had exhausted all his state appeals. By a 6–3 margin the Court affirmed the United States Court of Appeals for the Second Circuit's reversal of a district court denial of the petition.
United States v. Graham, 846 F. Supp. 2d 384, was a Maryland District Court case in which the Court held that historical cell site location data is not protected by the Fourth Amendment. Reacting to the precedent established by the recent Supreme Court case United States v. Jones in conjunction with the application of the third party doctrine, Judge Richard D. Bennett, found that "information voluntarily disclosed to a third party ceases to enjoy Fourth Amendment protection" because that information no longer belongs to the consumer, but rather to the telecommunications company that handles the transmissions records. The historical cell site location data is then not subject to the privacy protections afforded by the Fourth Amendment standard of probable cause, but rather to the Stored Communications Act, which governs the voluntary or compelled disclosure of stored electronic communications records.
The third-party doctrine is a United States legal doctrine that holds that people who voluntarily give information to third parties—such as banks, phone companies, internet service providers (ISPs), and e-mail servers—have "no reasonable expectation of privacy" in that information. A lack of privacy protection allows the United States government to obtain information from third parties without a legal warrant and without otherwise complying with the Fourth Amendment prohibition against search and seizure without probable cause and a judicial search warrant.
In re Application of the United States for Historical Cell Site Data, 724 F.3d 600, was a case in which the United States Court of Appeals for the Fifth Circuit held that the government can access cell site records without a warrant. Specifically, the court held that court orders under the Stored Communications Act compelling cell phone providers to disclose historical cell site information are not per se unconstitutional.
United States v. Quartavious Davis is a United States federal legal case that challenged the use in a criminal trial of location data obtained without a search warrant from MetroPCS, a cell phone service provider. Mobile phone tracking data had helped place the defendant in this case at the scene of several crimes, for which he was convicted. The defendant appealed to the Eleventh Circuit Court of Appeals, which found the warrantless data collection had violated his constitutional rights under the Fourth Amendment to the United States Constitution, but declined to order a new trial because the evidence was collected in good faith. The Eleventh Circuit has since vacated this decision pending a rehearing by the Eleventh Circuit en banc. United States v. Davis, 573 Fed. Appx. 925. On 5 May 2015, the en banc order upheld the use of the information. On 9th Nov 2015, the Supreme Court of the United States declined to hear this case on appeal.
United States virtual currency law is financial regulation as applied to transactions in virtual currency in the U.S. The Commodity Futures Trading Commission has regulated and may continue to regulate virtual currencies as commodities. The Securities and Exchange Commission also requires registration of any virtual currency traded in the U.S. if it is classified as a security and of any trading platform that meets its definition of an exchange.
Carpenter v. United States, 585 U.S. ___, 138 S.Ct. 2206 (2018), is a landmark United States Supreme Court case concerning the privacy of historical cell site location information (CSLI). The Court held that the government violates the Fourth Amendment to the United States Constitution when it accesses historical CSLI records containing the physical locations of cellphones without a search warrant.
Byrd v. United States, 584 U.S. ___ (2018), was a United States Supreme Court case that held that drivers of rental cars have rights protecting them from unconstitutional searches by police, even if the drivers are not listed on the rental agreement.
United States v. Miller, 425 U.S. 435 (1976), was a United States Supreme Court that held that bank records are not subject to protection under the Fourth Amendment to the United States Constitution. The case, along with Smith v. Maryland, established the principle of the third-party doctrine in relation to privacy rights.
A blockchain is a shared database that records transactions between two parties in an immutable ledger. Blockchain documents and confirms pseudonymous ownership of all transactions in a verifiable and sustainable way. After a transaction is validated and cryptographically verified by other participants or nodes in the network, it is made into a "block" on the blockchain. A block contains information about the time the transaction occurred, previous transactions, and details about the transaction. Once recorded as a block, transactions are ordered chronologically and cannot be altered. This technology rose to popularity after the creation of Bitcoin, the first application of blockchain technology, which has since catalyzed other cryptocurrencies and applications.
Digital Search and Seizure refers to the ability of the United States Government to obtain and read an individual's private digital correspondence and material under The Fourth Amendment of the United States Constitution.
The aerial surveillance doctrine is the legal doctrine in the United States of America that under the Fourth Amendment, aerial surveillance of an individual’s property does not inherently constitute a search for which law enforcement must obtain a warrant. Courts have used several factors–sometimes only one or a few, other times many or all of them–to determine whether the surveillance in question is a search in violation of one’s constitutional rights: the object of the surveillance, the technology employed, the duration of the surveillance, scope of aggregated information, and the vantage point from which the surveillance is conducted.
