The Supreme Court expressed deep reservations Tuesday about police use of GPS technology to track criminal suspects without a warrant.
But the justices appeared unsettled about how or whether to regulate GPS tracking, and whether they should look at other high-tech surveillance techniques in resolving this case.
The court heard arguments in the Obama administration's appeal of a court ruling that threw out a drug conspiracy conviction against Antoine Jones. FBI agents and local police did not have a valid search warrant when they installed a GPS device on Jones' car and collected travel information.
The justices were taken aback when the lawyer representing the government said police officers could install GPS devices on the justices' cars and track their movements without a warrant.
The court has previously ruled there is no expectation of privacy on public roads. But that decision came in a 1983 case involving the use of beeper technology, which still required officers to follow the vehicle they were tracking.
Justice Samuel Alito captured the essence of the court's concern when he said, "With computers around, it's now so simple to amass an enormous amount of information. How do we deal with this? Just say nothing has changed?"
Chief Justice John Roberts drew a comparison with artwork to explain the power of GPS surveillance. "You're talking about the difference between seeing a little tile and a mosaic," Roberts said.
Justice Department lawyer Michael Dreeben said it would be better for lawmakers rather than judges to set limits. Dreeben said the concerns expressed Tuesday were similar to those in the earlier high court case. Thirty years ago, Dreeben said, "Beeper technology seemed extraordinarily advanced."
He also sought to portray GPS use as one among many police tracking methods that do not call for a warrant. Police can go through people's trash, obtain information about who they call, even follow them round-the-clock without a warrant, he said.
GPS devices are especially useful in early stages of an investigation, when they can eliminate the use of time-consuming stakeouts as officers seek to gather evidence, he said.
For all the unease the court voiced in its questions to Dreeben, the justices seemed equally torn in questions to Stephen Leckar, Jones' lawyer, about how to impose limits on the police.
Justice Ruth Bader Ginsburg asked whether the use of video surveillance cameras is so different from getting information from a GPS device on a car. In London, Justice Elena Kagan said, cameras are everywhere.
"It's pretty scary," Leckar said.
Justice Antonin Scalia responded with evident sarcasm. "Well, it must be unconstitutional if it's scary," Scalia said.
More gently, Justice Stephen Breyer pointed out that English authorities have used video footage to prevent terrorist attacks.
The point of the questioning was to get Leckar to offer a principled way to draw a line that would still allow police to do their jobs without compromising people's rights.
Leckar said perhaps police could use the GPS device to follow someone for a day or one trip, without first getting a warrant. But that didn't appear to satisfy much of the court, either.
The GPS device helped authorities link Jones to a suburban house used to stash money and drugs. He was convicted and sentenced to life in prison before the federal appeals court in Washington overturned the conviction.
The appellate judges said the authorities should have had a warrant and pointed to the length of the surveillance -- a month -- as a factor in their decision.
An unusual array of interest groups backs Jones, including the Gun Owners of America, the Council on American-Islamic Relations, the American Civil Liberties Union and an association of truck drivers. The groups say GPS technology is much more powerful than the beeper technology police once employed in surveillance.
Other appeals courts have ruled that search warrants aren't necessary for GPS tracking.
The justices are considering two related issues, whether a warrant is needed before installing the device or using the GPS technology to track a vehicle. They could determine that the installation requires a warrant, leaving the knottier issues relating to tracking to another day.
A decision should come by spring.
The case is U.S. v. Jones, 10-1259.