There is no civil liberty attached to a wireless device contstantly transmitting information back to a central core and freely available to anyone with a radio tuned to UHF frequencies. Watch your cell phone everytime the little light blinks it's polling for data and possibly modifying local location tables at the cell control station.

In the United States, someone who probably lost a loved one due to a failed 911 call, incited some minoroty group that most likely won the hearts of a few people who eventually instituted the 911 regulation that forced cell phone companies to come up with some kind of way to locate a telephone. That is why I constantly preach, be careful what you scream for as a people. With newer technologies, such as GPRS that became much easier, becasue even at the time the FCC set a deadline for the system to be operational, it didn't work. Now it works a little, within a few hundred yards, or hundred feet if your lucky. I am not sure how someone could tell the instant you walk into a store that your are there, the cell phone company isn't doing it. They can barely keep people talking without interference and degraded signals and dropouts, and chances are you will lose the singnal walking into the building. My guess, and if it was me, I would snoop the IMEI being broadcast back to the control site and force a text message on you through a mass spam e-mail gateway. But I am not of that sort, and if I walked into a store that spammed me they can kiss my ass, and I'll go someplace else. Unless of course I chose to be notified on my own accord.

The FCC gave cell phone companies until 2001 to make it work. Now they have 4 more years, Phase 2 is dues in December of 2005. So it's getting better but in all situations new and expensive equipment must be deployed. Major cities are pretty decent, especially test beds. But hell, no one considers anthing less that a few hundred feet possible in terms of mass rollout. UNLESS, GPS receivers are imbeded. But at a few hundred feet someone should be able to see your burning car. If you look on the positive side of the technology. Or your girlfriend sees what pub your hidding out in. Bottom line, some carriers don't even want to spend the money on it and if they do, they are looking for ways to make up for the expense.