LawPundit alerted to this privacy rights landmark case previously at Landmark U.S. Supreme Court Case Upcoming Oral Argument: GPS Device Plant on Motor Vehicle by Police: When is it Legal?
The court has now decided the case, as reported by Jess Bravin at the Wall Street Journal Online in Supreme Court Reins In Police On GPS Trackers.
There was a 9-0 decision on the result in the case but an unusual 5-4 split on the legal reasoning, with Justices not aligning in their normal politically-oriented groupings.
Justice Scalia wrote the majority opinion, joined by Chief Justice John Roberts and Justices Anthony Kennedy, Clarence Thomas and Sonia Sotomayor, basing the majority decision on traditional principles of property, and finding that planting of a GPS tracking device on a motor vehicle violated private property rights.
That is the classic justification for requiring search warrants of private premises. The majority reasoning held that the Constitutional protection granted by the Fourth Amendment against unreasonable searches and seizures of "persons, houses, papers, and effects" extended to private property such as an automobile,
i.e. this reasoning protects "places".
The legal reasoning of the other four Justices, Ruth Bader Ginsburg, Stephen Breyer, Elena Kagan, and -- surprisingly -- the very conservative Justice Alito, concurring in judgment, was that planting a GPS tracking device on an automobile violated an individual's "reasonable expectation of privacy",
i.e. this reasoning protects "people".
The search and seizure standard in effect since 1967 is Katz v. U.S.,
United States Supreme Court case discussing the nature of the "right to privacy" and the legal definition of a "search." The Court’s ruling adjusted previous interpretations of the unreasonable search and seizure clause of the Fourth Amendment to count immaterial intrusion with technology as a search, overruling Olmstead v. United States and Goldman v. United States. Katz also extended Fourth Amendment protection to all areas where a person has a "reasonable expectation of privacy".Katz v. United States, , is a
Justice Scalia wrote that even surveillance without physical trespass may be "an unconstitutional invasion of privacy"—but, he added, there was no need to speculate on such problems until a specific case presented them to the court.
In any case, we will have to wait for a future case to explain the scope of the "reasonable expectation of privacy" standard in the modern digital world.