The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated. There is no resulting broad principle, however, that the Fourth Amendment constrains federal officials wherever and against whomever they act.As mentioned above, an automobile may be searched without a warrant they the police have probable cause to believe there is evidence of a crime in the vehicle. The Fourth Amendment prohibits the United States government from conducting "unreasonable searches and seizures. The Fourth Amendment's rule against unreasonable search and seizures means that police may not search you or your property unless one of the following is true:. Donor support is very important to us. This Fourth Amendment activity is based on the landmark Supreme Court case Brendlin v. California, dealing with search and seizure during a traffic stop. The Fourth Amendment of the federal Constitution, and a similar provision in the. California Constitution, prohibit unreasonable seizures.