"Until recently, one of the main civilian uses of G.P.S. was in devices issued by the criminal justice system to track offenders as a condition of their parole or probation. The new generation of tracking devices has moved well beyond that population and now takes many forms, from plastic bracelets that can be locked onto children to small boxes with tiny antennae that can be placed unobtrusively in cars.
'We are moving into a world where your location is going to be known at all times by some electronic device,' said Larry Smarr, director of the California Institute for Telecommunications and Information Technology. 'It's inevitable. So we should be talking about its consequences before it's too late.'
Some of those consequences have not been spelled out. Will federal investigators be allowed to retrieve information on your recent whereabouts from a private service like uLocate, or your cellular carrier? Can the local Starbucks store send advertisements to your phone when it knows you are nearby, without your explicit permission? "
But it is not just the unnerving effect of uncovering small lies that has some users of the technology worried. Like caller I.D., location devices lift the curtain on a zone of privacy that many Americans value, even if they rarely have anything serious to hide.
"Think back to when you were a teenager and your mom or dad said, `I don't want you to do this,' and you said, `yeah, yeah, yeah,' because you knew you could do it and they wouldn't know," said Graham Clarke, president of National Scientific, which makes several G.P.S. tracking devices. "Those days are gone now, because they actually can know."
Mr. Clarke recently installed a tracking device called Followit in the Jeep Wrangler of his 17-year-old son, Gordon. It alerts him if Gordon has exceeded 60 m.p.h. or traveled beyond preset boundaries.
Many more examples of tracking in the article -- tracking employees, tracking Alzheimer's patients, etc. This just gives me confidence in my idea -- that number portability will help companies develop long-term records of user movements, spanning years, and that phones won't be left on as often as they are now... Another unintended consequence of goverment mandates...