Upgrade Completed

Sometimes on news or blog sites with a facebook integrated comment section, the comment box already knows who I am even without me clicking on anything. Is this just on my end, or is Facebook really that creepy and these sites know who I am just because I go there while facebook is logged in but I haven't expressly told them I wanted to connect to their site through facebook?
/paranoid

And could we get a shortened list of the really obvious style elements so we know which not to complain about? I've noticed a few things.