<P> Following Katz, the vast majority of Fourth Amendment search cases have turned on the right to privacy, but in United States v. Jones (2012), the Court ruled that the Katz standard did not replace earlier case law, but rather, has supplemented it . In Jones, law enforcement officers had attached a GPS device on a car's exterior without Jones' knowledge or consent . The Court concluded that Jones was a bailee to the car, and so had a property interest in the car . Therefore, since the intrusion on the vehicle--a common law trespass--was for the purpose of obtaining information, the Court ruled that it was a search under the Fourth Amendment . The Court used similar "trespass" reasoning in Florida v. Jardines (2013), to rule that bringing a drug detection dog to sniff at the front door of a home was a search . </P> <P> In certain situations, law enforcement may perform a search when they have a reasonable suspicion of criminal activity, even if it falls short of probable cause necessary for an arrest . Under Terry v. Ohio (1968), law enforcement officers are permitted to conduct a limited warrantless search on a level of suspicion less than probable cause under certain circumstances . In Terry, the Supreme Court ruled that when a police officer witnesses "unusual conduct" that leads that officer to reasonably believe "that criminal activity may be afoot", that the suspicious person has a weapon and that the person is presently dangerous to the officer or others, the officer may conduct a "pat - down search" (or "frisk") to determine whether the person is carrying a weapon . This detention and search is known as a Terry stop . To conduct a frisk, officers must be able to point to specific and articulable facts which, taken together with rational inferences from those facts, reasonably warrant their actions . As established in Florida v. Royer (1983), such a search must be temporary, and questioning must be limited to the purpose of the stop (e.g., officers who stop a person because they have reasonable suspicion to believe that the person was driving a stolen car, cannot, after confirming that it is not stolen, compel the person to answer questions about anything else, such as the possession of contraband). </P> <P> The Fourth Amendment proscribes unreasonable seizure of any person, person's home (including its curtilage) or personal property without a warrant . A seizure of property occurs when there is "some meaningful interference with an individual's possessory interests in that property", such as when police officers take personal property away from an owner to use as evidence, or when they participate in an eviction . The amendment also protects against unreasonable seizure of persons, including a brief detention . </P> <P> A seizure does not occur just because the government questions an individual in a public place . The exclusionary rule would not bar voluntary answers to such questions from being offered into evidence in a subsequent criminal prosecution . The person is not being seized if his freedom of movement is not restrained . The government may not detain an individual even momentarily without reasonable, objective grounds, with few exceptions . His refusal to listen or answer does not by itself furnish such grounds . </P>

The fourth amendment protects against unreasonable searches by the government