The Supreme Court ruled unanimously today that the government must obtain a warrant before secretly affixing a GPS tracking device to a suspect's car. The case stemmed from an incident in which the FBI placed a tracker on a DC drug dealer's car, with the Obama administration arguing that Americans don't have a right to privacy while moving in public, Wired explains. The administration told the justices that it could track their cars as well if it wanted.
That didn't hold water with the court. "We hold that the government's installation of a GPS device on a target’s vehicle, and its use of that device to monitor the vehicle’s movements, constitutes a 'search,'" and hence violated Fourth Amendment protections, Antonin Scalia wrote in the majority opinion. The government had been leaning heavily on a 1983 case in which the high court had ruled that the government could legally use a "bird dog" beeper to track suspects.