In a move on a ruling that very well may put Batman's tights in a bundle, the Supreme Court voted unanimously this week that police, private investigators, and anyone else with a sweet tooth for tracking will have to get a warrant before attaching a GPS device to a vehicle they do not own. Of course monitoring a vehicle's movements had previously been called legal in a case against a drug dealer that'd been tracked for a month without a warrant, but now according to the Supreme Court, this tracking has been deemed "unreasonable." Tracking a person with a GPS device without a warrant is now deemed illegal under the 4th Amendment.
What this ruling does is take GPS devices and place them in the same category as a Police officer demanding that a person empty their pockets if they've got no real reason to do so. The word "search" is what's important here, and the Supreme Court has found it unreasonable to search a person, or track a person, as it were, without justifiable intent. Have a peek at some important bits from the ruling here:
The Government’s attachment of the GPS device to the vehicle,
and its use of that device to monitor the vehicle’s movements, constitutes a search under the Fourth Amendment.
(a) The Fourth Amendment protects the “right of the people to be
secure in their persons, houses, papers, and effects, against unreasonable searches and seizures.” Here, the Government’s physical intrusion on an “effect” for the purpose of obtaining information constitutes a “search.” This type of encroachment on an area enumerated in the Amendment would have been considered a search within the meaning of the Amendment at the time it was adopted.
You can check out the entire ruling in PDF form if you wish, noting especially how the addition of a whole new category of search is important to us all when speaking about privacy in our country. The image you see above comes from Jon Snyder and Wired, Snyder being the fellow on trial here as his movements were tracked by the government for 32 days without his consent via his car and a couple of GPS devices, one of them being the one you see in the image above.