Really interesting article by Robert McMillan on just how private your private online sessions happen to be. Well actually if you are paraniod it isn't perhaps even as bad as you might have thought but it isn't good. Without stealing Robert's thunder it would be fair to say that on average it is 94% bad (i.e., they can ID your browser - through some combo of browser, fonts, time zones, plug-ins etc... ) which would mean there is room for improvement...
I certainly would start applying some randomness to all those variables if I were some naughty Serbian or other sort about to embark on the cyber-naughtiness (I'm alluding to fraud rather than filth here). Move, counter, counter to the counter and so the game goes on: Cops and robbers... cops and robbers!
Anyway - check out Robert's article here.