Leave him banned for a month, that is a very long time and he will think twice next time if he wants to make a bad joke about someone!
backstabber - talking behind someone's back, flaming etc.
joke lover - making fun of people even though if others wont find that stuff as joke.
you probably heard from someone that ambrosia was at massive hacker attack, then forum, now servers. making a joke about all this stuff is just stupid, only little sick kids make such jokes about someone that feels very bad...