Are services like Facebook and twitter using the same oAuth mechanism for their own (mobile) apps as the rest of us? Or are the using some kind of “special mode” in oAuth which bypasses the permissions stuff etc. ?
Would really like to know how they are authenticating their users.
Facebook is not using oauth and have special login/private API for their own purposes. Only Facebook is 1st class citizen for these APIs and they don’t need to bother with public APIs.