GPS Stalking Devices

I don’t consider myself a “guru of technology” but recently my job necessitated purchasing a GPS for my car. As a survivor of the older technology of stalking (meaning pre GPS) I became suddenly aware of how this might raise all kinds of safety issues for “unsafe women.” trying to go about their daily lives. And this does not begin to address the new dangers for women with cell phones that contain a GPS system.
I have already heard of a women being stalked by her ex-husband. He placed a GPS device on her car. He then went to his work and was able to track her car from his employer’s computer.
How are the new technologies affecting your ability to stay safe?

Pamela