The US Supreme Court delved Tuesday into the issue of privacy amid 21st century technology, hearing arguments on whether police can use a GPS device attached to a vehicle to track a suspect without a search warrant.

The US government asked the justices to reinstate the conviction of Washington nightclub owner Antoine Jones for drug dealing which had been overturned by an appeals court which found the warrantless tracking "creepy" and "un-American."

At issue is whether by attaching a GPS, or Global Positioning System tracking device without a warrant, police violated the man's constitutional guarantee in the Fourth Amendment against unreasonable search and seizure.

The case has drawn wide interest from civil liberties groups amid concern that new technologies can be used to get around constitutional protections of privacy and other rights.

Deputy Solicitor General Michael Dreeben told the nine justices on the top US court that the GPS device simply monitored the suspect's location on public streets, which could be done by police visually without the need for a warrant.

The US government attorney said the GPS technology simply "can make police more efficient" and that "police efficiency has never been equated with an invasion of privacy."

But comments from the justices were skeptical.

"If you win this case, there is nothing preventing you from monitoring the movements of every citizen of the United States 24 hours a day," said Justice Stephen Breyer.

"If you win, you produce something that sounds like '1984,'" a reference to the George Orwell novel.

Justice Sonia Sotomayor said the surveillance could increase as technology improves.

Under the same logic used by the government, she said, "it would be OK to take a computer chip and put it on somebody's overcoat and follow them" without a warrant or "track people with smartphones."

Attorney Stephen Leckar argued on behalf of Jones that allowing the evidence to be used in court would give police "the capacity to engage in a grave abuse of liberties."

Leckar said the use of the tracking device was "an unreasonable invasion of privacy" and that police must obtain a warrant to avoid a constitutional violation.

But the justices pointed out that setting any standard is complex.

"What is the difference between following somebody for 12 hours and monitoring someone using GPS for 12 hours?" asked Justice Samuel Alito.

The case is seen as an important test of how far police can go in using technology to investigate and track suspects.

In the Jones case, police had obtained a warrant to place the device in the suspect's car, but it had expired. Police used the GPS device to track Jones to a stash house, where they found cocaine, weapons and drug paraphernalia. He was convicted of conspiracy to distribute cocaine and sentenced to life in prison.

An appellate court overturned the conviction, and Judge Alex Kozinski wrote in his opinion: "There is something creepy and un-American about such clandestine and underhanded behavior. To those of us who have lived under a totalitarian regime, there is an eerie feeling of deja vu."

At the Supreme Court hearing Tuesday, Chief Justice John Roberts pondered how far police could go in such investigations -- if authorities wanted to track the justices: "If you put a GPS on all of our cars and monitored our movements for a month, would that be OK?" he asked the Justice Department lawyer.

"The answer is yes," Dreeben replied. "The FBI could put surveillance on any individual."

Outside the court, co-defense lawyer Walter Dellinger said the admission by the government that a few thousands GPS devices are being used in similar cases was "not very reassuring" and said it was an "intrusion into the rights" of Jones and others, if no warrant is obtained.

Among those following the case, some say it is a preview of what is expected to be more critical case of whether police can use GPS-enabled smartphones to track individuals, also without a warrant.

The decision may shed light "on whether government agents are required to get a warrant before accessing location information generated by use of a cellular telephone, laptop computer, tablet computer, or other mobile computing device," according to the Center for Democracy and Technology, an advocacy group.

"While the methodology of mobile phone tracking differs from GPS... the privacy interests at stake are quite similar."