Florida v. Riley, 488 U.S. 445 (1989), was a United States Supreme Court decision which held that police officials do not need a warrant to observe an individual's property from public airspace.

[5]Also vital to the Court's ruling was the fact that the helicopter did not interfere with the normal use of the property: As far as this record reveals, no intimate details connected with the use of the home or curtilage were observed, and there was no undue noise, no wind, no dust, or threat of injury.

[6]Justice O'Connor felt that the plurality focused too much upon FAA regulations, "whose purpose is to promote air safety, not to protect [Fourth Amendment rights]."

She deviated from the plurality opinion in arguing that the frequency of public flight in the airspace was a necessary concern, and that the mere legality of such flights was insufficient to determine whether the defendant had a reasonable expectation of privacy: [I]t is not conclusive to observe, as the plurality does, that "[a]ny member of the public could legally have been flying over Riley's property in a helicopter at the altitude of 400 feet and could have observed Riley's greenhouse."

Like Brennan, Blackmun noticed that the main disagreement among these five justices was whether the government or the defendant had the burden of proof in establishing whether public flights above Riley's home were common or rare.