Beware of cookies. They are omni present and violating your on-line anonymity. If you want total control over which cookies stay on your computer and which cookies can be automatically deleted, then the Firefox extension, CookieCuller is for you. Normally you can clear-up your cookies using the Firefox >> Tools >> Clear Personal Data >> Cookies but it does not give you the possibility to retain your protected cookies. Remember that taking off cookies most often means that you’ve got to login from afresh into most of your favorite sites (rather annoying), so protect the cookies of your favorite and trusted sites like Google and allow automatic canceling of the unwanted cookies.