The U.S. Supreme Court on Monday said that police had illegally gathered evidence in their investigation of a suspected drug kingpin, and they overturned the conviction of the man. The man was convicted of being connected to a large drug operation. A major factor in police linking him to the drug operation was through a GPS device that they attached to the bottom of his car in order to track where he was going.

The Supreme Court justices voted unanimously to overturn the drug crime conviction, but they differed somewhat in their interpretation of the case and how it would apply in the future. The GPS device was believed to constitute unreasonable search and seizure, which is in violation of the Fourth Amendment. It wasn't decided yet, however, whether GPS survelliance itself is a violation of the Fourth Amendment.

Instead, the decision was largely hinged on the fact that the GPS was attached not in accordance with a search warrant that had been issued by a judge. It was put on too many days after the warrant was issued and in the state of Maryland rather than Washington, D.C.

The majority of justices decided to leave the questions of where the line between reasonable search and seizure is drawn as more surveillance technology is developed.

Source: The Washington Post, "Supreme Court: Warrants needed in GPS tracking," Robert Barnes, Jan. 23, 2012