Border search exception

The border search exception is a doctrine of United States criminal law that allows searches and seizures at international borders and their functional equivalent without a warrant or probable cause.
This doctrine is not actually an exception to the Fourth Amendment, but rather to the Amendment's requirement for a warrant or probable cause. Balanced against the sovereign's interests at the border are the Fourth Amendment rights of entrants. Not only is the expectation of privacy less at the border than in the interior, the Fourth Amendment balance between the interests of the Government and the privacy right of the individual is also struck much more favorably to the Government at the border. This balance at international borders means that routine searches are "reasonable" there, and therefore do not violate the Fourth Amendment's proscription against "unreasonable searches and seizures".