True, but how to create “Login with…” button who have feature that allows ONLY already registered site members log in with social profiles?
Main idea – there is button for registration (will sent e-mails with invite links also), after registration site moderator will check and accept/decline. After that registered and approved user will have possibility to log in into website with his/her Facebook and Twitter profile but if user is not approved by moderator, user cannot log in with social profile.