Are they tracking you? (Image: Jason Hawkes/Getty)

Should police in the US be able to attach a GPS location tracking device to someone’s car without having a search warrant? For many Americans that is a frightening thought. But depending upon the outcome of a case that began in the US Supreme Court last week, it could become a reality.

The US government brought the case after an appeals court overturned Antoine Jones’s conviction for running a drug-dealing ring. The Washington DC nightclub owner had been sentenced to life in jail based on evidence of regular trips to and from a property containing a massive cocaine stash.

This evidence was gathered by a GPS tracker that detectives had attached to his car. But they only attached the device after a search warrant had expired – so an appeal court overturned his conviction on the grounds that the evidence was illegally acquired.


The US Department of Justice thinks this is a dangerous precedent and that warrants should not be needed for GPS trackers to be used – as is the case in the UK. The department’s position is that the law needs to catch up with technologies like GPS, which is now just another crime-fighting tool.

US Deputy Solicitor General Michael Dreeben said he accepted that the fourth amendment to the US constitution protects a person’s home and effects – such as their car – against “unreasonable searches and seizures” by the state. But he told the nine Supreme Court justices that what a citizen “reveals to the world, such as his movements in a car on a public roadway” is not protected.

Warrant needed?

Jones was only tracked on public highways, Dreeben noted. And the suspect’s car could just as easily have been monitored by CCTV cameras or by having officers tail him and no warrants would have been required for such surveillance, he argued.

But Stephen Leckar, counsel for Jones, says the extent of the 24-hour-a-day, technology-mediated GPS monitoring was so intrusive and detailed that it amounted to a catch-all seizure of the data that described his client’s life. “The police have the capacity with GPS to engage in grave abuse of individual and group liberties,” he told the justices.

Both the American Civil Liberties Union and the Electronic Frontier Foundation back his view, and are opposed to the justices ruling that GPS tracking can be carried out without a search warrant. It is hard to guess how the court will eventually rule. Some of the justices saw the notion of warrantless tracking as Orwellian, suggesting that without warrants even Supreme Court justices could be tracked. Others saw the data acquired as publicly available, and that technology like CCTV and GPS had simply made it easier to access and compile.

When the case opened, Twitter users began swapping links to websites that sell GPS jammers. Using a jammer is illegal – but many of the websites where they can be bought are offshore and beyond effective regulation. A profusion of such jammers could risk creating GPS-free neighbourhoods where satnavs or cellphones – which use the GPS timing signal – cease to work.

But Ian Brown, a security and privacy researcher at the Oxford Internet Institute in the UK, believes law enforcement authorities could outsmart jammer users. “I think it is much more likely that those doing the tracking will combine GPS with other types of tracking technology, such as via mobile phone networks, and therefore prevent jamming becoming a significant issue,” he told New Scientist. However, some of the GPS jammers on sale online can also jam cellphone signals – so an arms race of sorts could ensue.

What happens next in the US depends on what the justices decide – a decision that must be made by next June. Installing a GPS tracker “may be a sneaky thing to do,” says Justice Antonin Scalia. “But every sneaky thing is not a trespass.”