Like many people today, I have a GPS (Global Positioning System) navigation system mounted semipermanantly in my car to help me get around when I'm out and about. Every once in a while, however, I find myself being asked a rather curious question to which I haven't really put together a rehearsed answer. That question is this: "If you're so consciencious about your privacy, why do you have a GPS unit in your car? Aren't you worried that you'll be tracked wherever you go by your GPS?"

The short and simple answer to that question is, "No, I'm not concerned …