The handy tracking device in your pocket

By ANDY COHEN / TIME

Smart phones do many things these days: surf the Internet, send e-mail, take photos and video (and — oh, yes — send and receive calls). But one thing they can do that phone companies don't advertise is spy on you. As long as you don't leave home without your phone, that handy gadget keeps a record of everywhere you go — a record the government can then get from your telephone company.

The law is unclear about how easy it should be for the government to get its hands on this locational data — which can reveal whether you've been going to church, attending a Tea Party rally, spending the night at a date's house or visiting a cancer-treatment center. A federal appeals court ruled last week that in some cases the government may need a search warrant. And while that's a step forward, it's not good enough. The rule should be that the government always needs a warrant to access your cell-phone records and obtain data about where you have been.

When you carry a cell phone, it is constantly sending signals about where you are. It "pings" nearby cell-phone towers about every seven seconds so it can be ready to make and receive calls. When it does, the phone is also telling the company that owns the towers where you are at that moment — data the company then stores away indefinitely. There is also a second kind of locational data that phone companies have, thanks to a GPS chip that is embedded in most smart phones now. This is even more accurate — unlike the towers, which can only pinpoint a general area where you may be, GPS can often reveal exactly where you are at any given moment within a matter of meters

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It is not hard to imagine that the government could also one day use cell-phone data to stifle dissent. Cell-phone records could tell them who attended an antigovernment rally. It could also tell them who is going into the opposition party's headquarters or into the home of someone they have questions about. Cell-phone data may be the most efficient way ever invented for a government to spy on its people — since people are planting the devices on themselves and even paying the monthly bills. The KGB never had anything like it.

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