Today, in some states in America, it is perfectly legal for the police to place a small GPS tracking device somewhere on the outside of your car without your knowledge and without a warrant being issued. In these states, all your driving data can be tracked by the authorities - telling them every time you went to your grocery store, your place of worship, and your doctor. The fact that this is considered legal in some states while in others it is not is a clear indication that legal professionals are still unclear as to whether or not GPS tracking without a warrant is unconstitutional.
Privacy, Surveillance and Unreasonable SearchAt the heart of this question are the issues of privacy, our protection against unreasonable searches, and the current surveillance activities of the police. As it stands today, a person's activity that is undertaken in the public sphere is considered non- private activity. If you drive your car to a public store you have no right to have this information private because it was done for all who would see it to see. The same goes for all trips along public roads or to locations within public space. Even travel to private places, like churches, doctors offices, psychiatrists, or a private residence, if done within public space, can be monitored by third parties without violating your privacy.
Which leads us to the current state of surveillance in the US - police are freely able to follow an individual as they travel around in public space without having to have a warrant to do so. If a suspect is taking his car to the store, the police can follow him there without any worries that they are performing an unreasonable search. This is all very clear in the law and has been for many years now.
But what happens when you substitute a police officer for a GPS tracking device? Pure confusion.
Is GPS Tracking the Same As Physical Surveillance?That is the million dollar question, and some states (like Wisconsin) say that it is exactly like physical surveillance while other states (like New York) say that it is not.
The judges in Wisconsin feel that GPS tracking is almost exactly like a person being sent to follow a suspect, except that this person will always be awake while providing extremely reliable information about the suspect. Not only will it be exact, it will also be extremely efficient, cheap, and environmentally friendly. The police will not have to use one of their officers to follow a suspect, letting them catch more criminals and save the police money, and it will reduce the number of cars on the road.
The judges in New York, however, felt that the accuracy of the GPS tracking devices is a little too powerful, especially when you consider the powerful information that one can get from tracking a person's cell phone. They had a great concern that the power of this technology was simply too great and that the surveillance capabilities of the police would be too great given the ease of use GPS provides.