From Fox News:

A federal appeals court will begin debating on Friday a privacy issue you probably hadn't considered: the government's ability to track your location at any time, if you carry a cell phone.

As cell phones have morphed from cordless communication devices into pocket-sized PCs, cellular providers have developed and honed the ability to pinpoint your location fairly accurately -- potentially to within 150 feet. This helps network operators connect your phone to the nearest cell tower and locate you in an emergency, a federally mandated feature called e911.

That feature could be a lifesaver if your car runs off a rural road on a dark night. But it also enables the authorities to know your location at all times when you're carrying your phone.

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