Top websites use device fingerprinting to secretly track users

A new study by KU Leuven-iMinds researchers has uncovered that 145 of the Internet's 10,000 top websites track users without their knowledge or consent. The websites use hidden scripts to extract a device fingerprint from users' browsers
http://www.spacewar.com/reports/Several_top_websites_use_device_fingerprinting_to_secretly_track_users_999.html