Anyone leery about their privacy rights being violated by misuse of modern technology should pay attention to a case argued before the U.S. Supreme Court this week.

The issue: Whether the government can attach Global Positioning System (GPS) tracking devices to vehicles without first obtaining a warrant. Short of that, is the government breaching Americans' privacy rights guaranteed in the U.S. Constitution? Is law enforcement trespassing on private property?

As the justices weigh those questions, it's our hope that they'll do everything possible to safeguard the search-and-seizure standards outlined in the Constitution's Fourth Amendment -- the amendment that protects Americans from "unreasonable" intrusions by law enforcement.

But what "unreasonable" means in the face of 21st-century technology isn't clear-cut. Some federal judges have ruled that no one can expect privacy for behavior carried out on public streets. This makes the Supreme Court's eventual ruling all the more critical.

The specific case before the court involves Antoine Jones, a Washington, D.C., nightclub owner sentenced to life in prison. He was convicted of drug trafficking in 2008 with information gathered from a GPS device that the FBI secretly put on his Jeep.

The FBI used the device to record Jones' whereabouts every 10 seconds, 24 hours a day for nearly a month. Jones won on appeal after his lawyers argued that the extended use of GPS tracking technology by law enforcement violated his Fourth Amendment protection from unreasonable search.

In presenting the government's case to the Supreme Court on Tuesday, Deputy U.S. Solicitor General Michael Dreeben argued that citizens' movements on public roadways aren't protected by the Fourth Amendment. That didn't appear to sit well with Chief Justice John Roberts.

He asked whether Dreeben felt that law enforcement was entitled to put GPS devices on the Supreme Court justices' vehicles and track their whereabouts for a month. Indeed, Dreeben said, "the justices of this court" should have no expectation of privacy "when driving on public roadways."

Justice Samuel Alito said that the privacy Americans enjoyed before the Internet age had little to do with legal protections.

"It was the result simply of the difficulty of traveling around and gathering up information," he said, adding that computers made it easy to amass enormous amounts of data on individuals.

Justice Stephen Breyer painted a more frightening scenario, invoking George Orwell's futuristic novel "1984": "If you win this case, then there is nothing to prevent the police or the government from monitoring 24 hours a day the public movement of every citizen of the United States."

A decision in the case, United States vs. Jones, is expected by next June. The Supreme Court should uphold the Appeals Court ruling that the government's tracking of Jones was unreasonable.

Law enforcement should be required to obtain a court order before launching the kind of invasive and lengthy tracking as conducted on Jones. But this case isn't merely about Jones: It's about safeguarding the privacy rights of every American.

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