The U.S. Supreme Court will be weighing on how far the government can go in using technology to track its citizens.
The case, to be heard this November, involves whether police and prosecutors in Washington state needed a warrant to attach a GPS tracking device to a suspect's car.
Lower courts have been divided in their rulings on the issue.
One law professor told the New York Times that the case requires the Supreme Court to decide whether modern technology has turned law enforcement into Big Brother - able to monitor and record every move citizens make outside their homes.
In a lower appeals court ruling last year, a three-judge panel said that the government was simply seeking too much information.
"Repeated visits to a church, a gym, a bar or a bookie tell a story not told by any single visit, as does one's not visiting any of those places in the course of a month," wrote Judge Douglas H. Ginsburg, on the U.S. Court of Appeals for the District of Columbia Circuit.
He added: "A person who knows all of another's travel can deduce whether he is a weekly churchgoer, a heavy drinker, a regular at the gym, an unfaithful husband, an outpatient receiving medical treatment, an associate of particular individuals or political groups - and not just one such fact about a person, but all such facts."
Some judges say the world of institutionalized mass surveillance is quickly approaching.