The ability (whether for mods or for all) to 'block' a user from a thread, and 'block' PMs from them would be helpful against troll and in other situations. Perhaps not exactly that, but something similar.
He/She'll get banned, but until he/she does he/she can still mess with the forums. The ability to block the user from threads he/she is messing with would be useful for 'damage control'.
I honestly don't think it would be worth the effort.
