Why Your Metadata Is Your Every Move

The metadata that the National Security Agency collects on all calls in the U.S. is not just what's on a phone bill, as the program's supporters have claimed. Your phone bill lists some of the same things the NSA's collecting — numbers dialed, length of all — but does not list the geolocation of each of your calls. It is that final piece of data — where you made your calls — that tells the government everything about your life. The government doesn't need to listen to your calls. Because it already knows where you are, and that does matter. In a paper published in Nature's Scientific Reports last year, MIT researchers found that with cell phone call metadata from 1.5 million anonymous people, they could identify a person easily with just four phone calls. As Foreign Policy's Joshua Keating explains, they didn't need names, addresses, or phone numbers. They only used time of the call and the closest cell tower.