[cinquemb]

I'm not following either.

If such interactions happen in the "open", facebook is then encrypting information relating to such "open" interactions, so that people already familiar with things like pgp/gpg (of which, I assume who also know what email headers are) can know that such "open" interactions came from facebook and that such information regarding "open" interactions was not modified in transit?

I guess "completely out in the open" means different things to different people…