"It does take time to reconcile new technology with legal principle," says Michael Scott, a clinical associate professor at the University of Wisconsin law school in Madison who specializes in research on the police. "We saw this with wiretapping in the 1960s. At one time, it was unthinkable: How could someone listen in on a private phone conversation? We had to rethink our expectation of privacy."
Shifting privacy standards?
The US standard on searches and seizures considers whether there is "a reasonable expectation of privacy." Typically, the Supreme Court has taken a "rather ungenerous view" of that expectation, says John Burkoff, a professor at the University of Pittsburgh's School of Law. "But those rulings came from a period of time when we didn't have the kind of technology that we have today."
More recently, the court has distinguished between devices in common use and those that aren't. If a device is readily available, then there isn't a reasonable expectation of privacy, Professor Burkoff says.
Unfortunately, he adds, GPS devices are commonly used today.
"All tracking technology is a double-edged sword," says Professor Scott, pointing out that people have already voluntarily given up some privacy rights. "If you buy Onstar [a car security service], you allow the company to monitor your car. You give it up when you buy electronic passes to go through the tolls.... You've got people putting GPS [devices] in their children's backpacks. Those trends, I think, will influence the courts."