The New York Times today has a nice opinion piece by Adam Cohen that does a good job of laying out the concerns about locational privacy that EFF and other privacy advocates have raised:

A little-appreciated downside of the technology revolution is that, mainly without thinking about it, we have given up “locational privacy.” Even in low-tech days, our movements were not entirely private. The desk attendant at my gym might have recalled seeing me, or my colleagues might have remembered when I arrived. Now the information is collected automatically and often stored indefinitely.

Privacy advocates are rightly concerned. Corporations and the government can keep track of what political meetings people attend, what bars and clubs they go to, whose homes they visit. It is the fact that people’s locations are being recorded “pervasively, silently, and cheaply that we’re worried about,” the Electronic Frontier Foundation said in a recent report.

People’s cellphones and E-ZPasses are increasingly being used against them in court. If your phone is on, even if you are not on a call, you may be able to be found (and perhaps picked up) at any hour of the day or night. As disturbing as it is to have your private data breached, it is worse to think that your physical location might fall into the hands of people who mean you harm.

This decline in locational privacy, from near-absolute to very little in just a few years, has not generated much outrage, or even discussion.

For more discussion of why this problem exists, and what needs to be done to solve it, check out EFF's whitepaper, On Locational Privacy, and How to Avoid Losing it Forever.