EFF: Web Browsers Leave 'Fingerprints' Behind as You Surf the Net: "The Electronic Frontier Foundation reports that most web browsers have
unique signatures that create identifiable 'fingerprints'. 'The
findings were the result of an experiment EFF conducted with volunteers who
visited http://panopticlick.eff.org/. The
website anonymously logged the configuration and version information from
each participant's operating system, browser, and browser plug-ins --
information that websites routinely access each time you visit -- and
compared that information to a database of configurations collected from
almost a million other visitors. EFF found that 84% of the configuration
combinations were unique and identifiable, creating unique and identifiable
browser 'fingerprints.' Browsers with Adobe Flash or Java plug-ins
installed were 94% unique and trackable.'"
