How to disable authentication for a particular user

["D G Teed" <donald teed gmail com>]

We have a series of authentication systems,
and when an account becomes compromised on the weekend,
it would be handy to be able to disable that user
without involving 3 systems admins on the different
authentication systems.  In this case I'm working
with pam_unix , pam_ldap and pam_winbind auth
modules and imap authentication.  Any are sufficient,
so I need to block them all.

Can anyone suggest a way to achieve this by having
a list of disabled or blocked user accounts which pam will
look at?

--Donald