Peter Eckersley (66542)
writes "The EFF has launched a research project called Panopticlick, to determine whether seemingly innocuous browser configuration information (like User Agent strings, plugin versions and, fonts) may create unique fingerprints that allow web users to be tracked, even if they limit or delete cookies. Preliminary results indicate that the User Agent string alone has 10.5 bits of entropy, which means that for a typical Internet user, only one in about 1,500 (2 ^ 10.5) others will share their User Agent string.
If you visit Panopticlick, you can get an reading of how rare or unique your browser configuration is, as well as helping EFF to collect better data about this problem and how best to defend against it."Link to Original Source