From another forum (not my idea):
I had an idea for a way to really mess with the heads of people who need to be banned from online fora. Create a way for that person's account to remain otherwise active, but with the following adjustment: Any post he sends will be visible only to him; no one else will see it. A faux "post count" will appear to him, making it appear as tho' his messages are being posted as normal; however, it will only be him seeing it. The only clue he gets as to his new status is if he looks at the forum while not logged in,and notices none of his posts are visible.
Moderators and admins can have great fun seeing how long it
takes this fool to notice no one ever responds to his posts.
Sufficiently sadistic?