It’s Tracking Your Every Move and You May Not Even Know

Tracking a customer’s whereabouts is part and parcel of what phone companies do for a living.

Every seven seconds or so, the phone company of someone with a working cellphone is determining the nearest tower, so as to most efficiently route calls. And for billing reasons, they track where the call is coming from and how long it has lasted. “At any given instant, a cell company has to know where you are; it is constantly registering with the tower with the strongest signal,” said Matthew Blaze, a professor of computer and information science at the University of Pennsylvania who has testified before Congress on the issue.