.NET Cowboy

Unless you explicitly give permission to use your location, interested parties (like, say, advertisers) can only track you with geolocation to within a radius of about 200 kilometers. But researchers in China and the U.S. have figured out a way to get closer—much closer. With a three-stage system using Google Maps, these researchers can, according to New Scientist, get as close as a few hundred meters.

Yong Wang, a computer scientist at the University of Electronic Science and Technology of China in Chengdu, developed a three-stage system to narrow the radius of geolocation without requiring the user’s permission. The first stage is the one that’s currently used: A packet is sent to the target, and the time it takes to to bounce back is converted into a (very vague) distance. But Wang took it further by realizing that many large organizations, like businesses and schools, usually have their servers in-house, meaning the IP addresses can be tied to a physical location that’s easily found. If an IP address is linked to a university, you can just look that university up on Google Maps and have a pretty good idea that the user of the IP address is somewhere nearby.