Fourth Amendment case law deals with three main issues: what government activities are "searches" and "seizures," what constitutes probable cause to conduct searches and seizures, and how violations of Fourth Amendment rights should be addressed. Early court decisions limited the amendment's scope to physical intrusion of property or persons, but with Katz v. United States (1967), the Supreme Court held that its protections extend to intrusions on the privacy of individuals as well as to physical locations. A warrant is needed for most search and seizure activities, but the Court has carved out a series of exceptions for consent searches, motor vehicle searches, evidence in plain view, exigent circumstances, border searches, and other situations.