Buddy beacons or stalker cells?

Today's New York Times comments on new technologies that make cell phones "buddy beacons" (or stalker tools):

Cellphone as Tracker: X Marks Your Doubts - New York Times

THE diminutive cellphone is turning out to be the most clever of devices. As it connects to more networks, stores more kinds of data, delivers more kinds of entertainment — wherever we happen to be — it effectively becomes the most personal computer we own.

Now, as more of the handsets are equipped to use the Global Positioning System, the satellite-based navigation network, we are on the verge of enjoying services made possible only when information is matched automatically to location. Maps on our phones will always know where we are. Our children can’t go missing. Movie listings will always be for the closest theaters; restaurant suggestions, organized by proximity. We will even have the option of choosing free cellphone service if we agree to accept ads focused on nearby businesses.

None of this entails anything exotic. The technology has been ready for a while, but not the customers. Prospective benefits have seemed paltry when placed against privacy concerns. Who will have access to our location information — present and past? Can carriers assure us that their systems are impervious to threats from stalkers and other malicious intruders or neglectful employees — or from government snoops without search warrants? Contemplating worst-case scenarios, our hands holding these very mobile devices have been frozen, hesitant to turn the location beacon on. Are we finally ready to flip the switch? ....