From Threat Level:

The home-sniff case, also arriving from the Florida Supreme Court, tests a decade-old U.S. Supreme Court precedent in which the justices ruled that police need a warrant to use thermal-imaging devices outside a house to detect marijuana-growing operations, saying it amounted to a search. In that case, the high court ruled in 2001 that “rapidly advancing technology” threatens the core of the Fourth Amendment “right of a man to retreat into his own home and there be free from unreasonable governmental intrusion.”