Debate centers on whether the home holds special legal sanctity against warrantless search, unlike an automobile.
In Katz v. United States, 389 U.S. 347 (1967), electronic eavesdropping devices attached to the outside of a phonebooth or a home were deemed to violate the unreasonable search and seizure clause of the Fourth Amendment to the United States Constitution, because the interior private life of the homeowners was exposed along with information about illegal activity.
In Illinois v. Caballes, 543 U.S. 405 (2005), the Supreme Court ruled that a minimally intrusive warrantless dog sniff of the car was constitutional at traffic stops.
Justice Stevens asserted that the Kyllo search was only unconstitutional due to the fact that it revealed certain aspects of the home besides the presence or absence of contraband.
Florida v. Jardines (2013) was Supreme Court case that decided the legality of deploying drug-sniffing dogs around the perimeter of homes without a search warrant.