Warrants are issued from court authorized law enforcement agents, such as police officers, to arrest individuals and to conduct searches. Warrants are required because the Fourth Amendment of the U.S. Constitution guarantees that a citizen cannot be illegally searched and seized. By requiring a warrant, courts are protecting those Fourth Amendment rights. The courts apply a warrant requirement in certain situations because each citizen has "an expectation of privacy." It is important to understand that the Fourth Amendment protects people, not places.