User bans allow you to restrict access to a chat community for a
specific user or group of users, identified by:
Domain name or IP address (This restriction
prevents an entire domain from gaining access to a chat
A user ban can be in effect indefinitely (from the point created
forward), or for a specific time period. You define one ban for
each community, so a user banned from one chat community may be
able to access another community on your system.