http://www.pcworld.com/article/192648/browser_fingerprints_a_big_privacy_threat.html?tk=nl_dnx_h_crawlThe method pulls together innocuous data about your browser, such as plug-ins, system fonts, and your operating system. Alone, they don't identify you. Together, they're a digital fingerprint.

More Than a Rumor
Peter Eckersley, a staff technologist with the EFF, says he and his colleagues decided to create the site when he heard rumors about this kind of tracking. He wanted to see how accurate it might be. Well, it's pretty accurate. And as it turns out, its use is more than a rumor. Browser fingerprinting was developed for banks to employ to prevent fraud. But now one company, Scout Analytics, offers it as a service to Web sites, and it collects not just browser data but also data about how you type--things like your typing speed and typing patterns.