The Fourth Amendment to the U.S. Constitution explicitly protects "[t]he right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures." The U.S. Supreme Court has consistently found that surveillance is comparable to a search and that it therefore ordinarily requires the subject's consent or a valid warrant. Unfortunately, our executive branch doesn't always pay attention to what the U.S. Supreme Court says.

