I'm also having the same sort of the same issue. For the past almost year I have been able to use facebook chat though pidgin (using the Facebook(XMPP)) plugin, but the past week any time I try and log in I get the following
and the following IM shows up from facebook
I have tried numerous times logging in logging out even went so far as to deactivate and reactivate my facebook but to no avail am I able to get it to work.
(12:11:33 AM) chat.facebook.com: Your account is temporarily unavailable. Regain access by logging into your account from your computer's web browser: http://www.facebook.com/
Should probably be stated I'm using Xubuntu 12.04 and Pidgin 2.10.6
EDIT - I just noticed I've brought back a thread from 4 months ago I'm terribly sorry for that.