The warrant must be based on probable cause. This is known as the "warrant requirement.The Fourth Amendment protects you against illegal search and seizure. So does the Texas state constitution. The amendment requires that probable cause be proven before anyone's items are searched through or taken. The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated. The Fourth Amendment does not prohibit the warrantless seizure of evidence of a crime in plain view, even if the discovery of evidence was not inadvertent. A search warrant is needed whenever law enforcement officers want to conduct a search or seizure. As part of the Bill of Rights, the Fourth Amendment to the U.S. Constitution guards against any actions of unreasonable search and seizure. The Fourth Amendment of the U.S. Constitution protects people from random and arbitrary stops and searches.