And, according to the Obama Department of Justice, should be used as such.
A bit of context: the actual brief requesting that law enforcement officials not be required to show probable cause before seizing cell phone records tracking your movement was filed by U.S. Attorney Mary Beth Buchanan, a Bush holdover who has refused to tender her resignation under the new administration. President Obama has not seen fit to terminate her, despite the fact that her philosophies are quite divergent from his own. As such, by choosing to keep her on, he is responsible for any briefs she files. Her most notorious case has been the prosecution of Tommy Chong for shipping drug paraphernalia through the mail. Now she wants access to your where-abouts by tapping into your cell phone records. Awesome! Somebody's been watching too many movies:
But if you're a law-abiding citizen, you've nothing to worry about, right? Unless, of course, you're engaged in constitutionally-protected free speech which upsets the establishment, such as an anti-war demonstration or a tea party demonstration. Say they want a list of names of people at that demonstration. Anybody with a cell phone (which is most people these days) can be tracked. Say they start a police riot and want to press trumped-up charges against anybody at that demonstration, both to discredit the demonstration and to send a message to anybody who gets any ideas about standing against them. You see where this is going.
The real people who would need to be concerned would be the organizers of such a rally. Some of these things can get quite large, and without some sort of organized presence behind them, can get unwieldy, potentially chaotic. What better way to communicate than by cell phone? Well, I'd recommend purchasing a pre-paid cell phone. They can track that, but they'd have to know who they're tracking. Some require you to register in order to use it; these are a bad deal and defeat the purpose. You want use of the technology without having to have your movements tracked. For your average Joe Protestor? Leave your cell phone at home, or else pull the battery if you want to keep it on hand in case of an emergency. Even if you turn it off, the phone still transmits and receives signals. Only pulling the battery stops the signals.
Best bet for those who don't actually have a need for a mobile phone but just keep it out of convenience: get a land line. It's cheaper, and these days if you really need a cell phone for a specific purpose, you can pick up a cheap disposable pre-paid phone for $30. It's what I do any time I go back to the states. I've already discontinued my GuamCell service and will be picking up a land line when I get back to Guam.
That's a tip for activists, not average folks who don't represent a threat to the status quo.