Security researchers at CA have found that Facebook is now collecting information about your activities on partner sites regardless -- this is important -- regardless of whether you have opted out or even whether you are logged in to Facebook. Also see the linked follow-up post (slightly more technical, http://snipr.com/1utzp). I am not usually really worried by advertising-related privacy issues, but the fact that Facebook now tracks you when you're logged out of the site -- and the additional fact that they are publicly misrepresenting this capability -- is a little unnerving.