Amendment IV

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.

The fourth amendment protects the rights of all citizens, whether law-abiding or criminally motivated. Without such protection, even the most legally conscious citizens might be in danger of arrest and unlawful prosecution.