An Illegal Search, by GPS

[Commentary] In a landmark 1967 case, the Supreme Court ruled that evidence from a wiretap on a phone booth was obtained unconstitutionally. Despite the public nature of a phone booth, the tap violated the defendant's privacy under the Fourth Amendment. "Wherever a man may be," the court explained, "he is entitled to know that he will remain free from unreasonable searches and seizures." Fast forward to today, when courts are wrestling with the question of whether new technology requires them to think differently about what is a reasonable expectation of privacy. In August, three judges on the United States Court of Appeals for the District of Columbia (two conservatives, one liberal) ruled unanimously -- and correctly -- that police violated the Constitution when they hid a GPS device on a person's car and tracked his every move without a valid warrant. Digital technology raises questions about differences between cyberspace and the physical world, which most search-and-seizure laws deal with. In showing why a powerful advance in technology calls for significantly greater protection of privacy, the three-judge panel provided an important example of how the law can respond to new circumstances.