Dear Bach, thanks for the quick reply.
I will add more details so that my question can be more clear: I run a school website with a lot of users that can add or modify articles.
They are Managers (backend), Publisher (frontend), Editors (frontend) and Authors (frontend).
I added my Facebook profile (the one that is the admin of the Fan Page) and I see that the Social Auto Publish box appear to other users too. This is quite correct since I want that my Managers, Publisher and Editors could post on Facebook Page (using my FB account is ok for me).
I just want that Authors could not see the Auto Publish box: they only edit School Library articles that will never go on Facebook.
At the moment, I dont' see how to manage this kind of group access management
Regards