Rights & liberties
Fourth Amendment
Protects against unreasonable searches and seizures and requires warrants to be based on probable cause and to describe specifically what will be searched.
In full
A search occurs when the government intrudes on a reasonable expectation of privacy or physically trespasses to gather information. Warrantless searches are presumptively unreasonable, subject to established exceptions. Carpenter v. United States (2018) extended protection to historical cell site location data, an important recognition that digital records can be as revealing as a home.
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A plain-language explanation for civic education, not legal advice. When in doubt, the official source named above controls.