The lawyers and justices referred to 1984 six times during the oral argument.
The case before the court, United States v. Jones, involves a Washington, D.C., nightclub owner, Antoine Jones, who was suspected of trafficking cocaine. Police placed a GPS device on the underside of Jones's Jeep Cherokee and followed his movements for more than four weeks.
Using the evidence obtained from the GPS device, a court convicted Jones and sentenced him to life in prison. An appeals court reversed the conviction, ruling that tracking his movements without a warrant violated his Fourth Amendment rights protecting him from unreasonable searches and seizures.
In his argument before the Supreme Court, the attorney for the government, Michael Dreeben, argued there is little difference between monitoring a car on public streets using a GPS device and police surreptitiously tailing a suspect.
Dreeben pointed out that the court ruled in 1983, in United States v. Knotts, that police can use a beeper device to track a suspect's car on public streets.
But Chief Justice John Roberts noted that police had to stay near the beeper to receive its signal.
"That was 30 years ago," Roberts said. "The technology is very different and you get a lot more information from the GPS surveillance than you do from following a beeper."
Justice Ruth Bader Ginsburg questioned Dreeben about whether people have an expectation of privacy outside of their homes.
"I think you answered the question that the government's position would mean that any of us could be monitored whenever we leave our homes," Ginsburg said. "That is the end point of your argument, that an electronic device, as long as it's not used inside the house, is okay."
Justice Sonia Sotomayor worried that if the court allows police to install GPS devices without a warrant, the practice could become widespread.
"The GPS technology today is limited only by the cost of the instrument, which frankly right now is so small that it wouldn't take that much of a budget, local budget, to place a GPS on every car in the nation," she said.
Sotomayor also considered how the police might use other technologies to track people.
"Under your theory … you could monitor and track every person through their cell phone," she said to Dreeben.
But the justices also asked tough questions of Jones's lawyer, Stephen Leckar, trying to distinguish GPS-tracking from police tailing suspects or monitoring them with public security cameras.
"What is the difference in terms of one's privacy whether you're followed by a police officer for 12 hours and you don't see the officer or whether you're monitored by GPS for 12 hours?" Justice Samuel Alito asked.
"I'm told that if somebody goes to London, almost every place that person goes there is a camera taking pictures, so that the police can put together snapshots of where everybody is all the time," Justice Elena Kagan said. "So why is this different from that?"
Leckar said such constant monitoring is "pretty scary."
"Well, it must be unconstitutional if it's scary," Scalia interjected sarcastically. "I mean, what is it, the 'scary provision' of what article?"
Breyer pointed out that security cameras in London helped to foil a terrorist bombing plot.
Leckar argued that cameras are different than GPS devices because GPS devices target specific individuals.
Scalia suggested it should be the job of state legislatures to enact laws to protect citizens from overreaching police surveillance.
"Don't we have any legislatures out there that could stop this stuff?" Scalia asked.