I believe -and people can correct me if I'm wrong- the way they do it is through all the sites with integrated Facebook items: "Share this", "Comment" etc. The

I believe -and people can correct me if I'm wrong- the way they do it is through all the sites with integrated Facebook items: "Share this", "Comment" etc. The cookies they use to track you are sitting on your drive regardless of your facebook status (logged in/out) and can simply be retrieved the next time you log in or link accounts.