The 4th Amendment to the US Constitution was ratified on December 15, 1791 as part of the Bill of Rights (the first 10 amendments). It is a protection for US citizens against unreasonable search and seizure. The U.S.A. government at all levels is guilty of flagrant and systemic violations of the 4th Amendment.
Text of the 4th Amendment
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.