The app that was written by Apple, or by Blackberry, had to ask you for your password first (or possible use a different kind of authentication were you had to

The app that was written by Apple, or by Blackberry, had to ask you for your password first (or possible use a different kind of authentication were you had to allow access). Without that, they could not send the "right bytes", and thus, the Facebook server would not send back any private information. In other words, it worked exactly like the Facebook app written by Facebook itself.