“What users may not realize is how much data they’re already sharing. This new style of Facebook Connect actually mirrors the behavior of Facebook itself. When you visit a Facebook application for the first time, it automatically knows who you are and can access your public data. When you then click “Allow” to authorize the app, you give it access to all of your private data. Currently, an external web site knows nothing about you until you click “Connect.” If you do click, it has the same access to your private data as an authorized application. Now, Facebook is letting sites initially act like new applications by giving them access to your public data prior to full authorization.
I’m inclined to think of this as unacceptable. I want to be anonymous on the Internet unless I explicitly choose otherwise. Facebook is switching the default, and it’s not going to happen without a fight.