An anonymous reader writes "'Snooping on the Internet is tricky. The network is diffuse, global, and packed with potential targets. There's no central system for identifying or locating individuals, so it's hard to keep track of who is online and what they're up to. What's a spy agency to do?' In a Slate op-ed, Ed Felten explains how consumer tracking makes the NSA's job much easier. Felten was the first-ever Chief Technologist at the Federal Trade Commission, serving as the agency's lead technical expert on privacy issues. Now back in academia, he argues that the NSA gets a 'free ride on the private sector,' from distinguishing users, to pinpointing geolocation, to slurping up network traffic."