Someone asked me if I could create a Facebook fan page where the poster's profile would be blacked out if the posted on it. Is something like that possible?
I don't think that's possible. If the poster on your fan page wants to keep his/her profile exclusive only to his/her friends, he/she needs to set it in his/her privacy settings. That's the only best thing so far.
I have a fan page account in facebook, tried to edit the setting on my own privacy settings and found nothing that can keep my fans' profiles in private.
In my openion off your the first person to "like" it on the list . people will realize your the one who made it right away..