I think so. Since you have a global positioning device, you can be tracked by anyone, not jsut selective people.

No. unless the GPS has a tracking feature built in such as on the Onstar car GPS. The basic ones hunters and hikers buy are not tracked because they are only a one way device. The GPS senses where it is by measuring the distance from the GPS satelites. There are no identifying codes for a GPS built in that I am aware of, unless its an added "feature" you would have to pay for.

While it may be technically possible to build a device that can find and track an unshielded radio receiver when it is turned on, most GPS units are not built to transmit anything - including their location, and no external device can "force" them to divulge it if they aren't designed to do so. There are so many GPS receivers out there, it is unlikely they could identify and track yours unless they already know where you are. Having said that, it may be possible for someone with the right kind of high tech spy equipment to point an extremely highly amplified directional antenna at your GPS and read and decipher the electrical signals being sent to the LCD display or other internal electrical activity. Of course, if they already know where you are so they can point their ultrasensitive spy equipment at you, they don't need to know what your GPS says... One other thought... the powers would have to know who owned each serial number and store all that data somewhere... how many of these devices are there? millions? How would they know who owned them all? Or who was currently using a particular one? It seems pretty unlikely. If you are really worried about it, take the batteries out of it or leave it at home when you go somewhere you don't want them to know about, but really, don't worry about it.