New Block III GPS Satellite
In a recent demonstration, a GPS expert showed how a hacker can easily exploit a weakness to hijack a luxury yacht. spaceref.com

Now that a federal ruling has allowed the FBI to hook up a GPS device to a Missouri man's car without a warrant, will jack-booted thugs be coming in the night for the rest of us? That depends now on what the Supreme Court says about the practice, although they won't rule on the case until later this year. They will be hearing a different case, but it is on the warrentless GPS topic. The latest ruling is just one of several decisions around the country recently that have supported warrentless GPS monitoring. Magistrate David Noce, a Missouri federal judge, said the FBI could place the device on Fred Robinson's car in 2010 because Robinson could not expect a reasonable amount of privacy on the outside of his car.

Robinson was suspected of cheating the government out of money by using phoney timesheets at his job in the city of St. Louis' treasurer's office. Here is what Noce had to say:

Here, installation of the GPS tracker device onto defendant Robinson's Cavalier was not a 'search' because defendant Robinson did not have a reasonable expectation of privacy in the exterior of his Cavalier. Agents installed the GPS tracker device onto defendant's Cavalier based on a reasonable suspicion that he was being illegally paid as a 'ghost' employee on the payroll of the St. Louis City Treasurer's Office.

Installation of the GPS tracker device was non-invasive; a magnetic component of the GPS tracker device allowed it to be affixed to the exterior of the Cavalier without the use of screws and without causing any damage to the exterior of the Cavalier. The GPS tracker device was installed when the Cavalier was on a public street near defendant's residence. Installation of the GPS tracker device revealed no information to the agents other than the public location of the vehicle. Under these circumstances, installation of the GPS tracker device was not a search within the meaning of the Fourth Amendment.

The case was argued under fourth amendment rights (search and seizure), although Robinson and his team wished the case to be considered a first amendment violation.

Federal agents use GPS monitoring thousands of times per year, according to a Wired.com report, and one official even said the government was free to use the devices on members of the Supreme Court without warrants if they had to. Justice Breyer took exception to that notion in particular, and warned the U.S. was in danger of allowing the government to monitor anybody at anytime.