It appears that riskarb was posting insults and profanity in other people's journals which ultimately generated some complaints from other members. Upon receiving these complaints, Magna deleted those posts and told Riskarb to back off from the insults. Riskarb then hurled a bunch of obscenities directly at Magna, which ultimately resulted in him getting banned.
I support this action. Any member (no matter how long they've been around) who repeatedly insults other members and moderators with vulgar names like "cunt", as in this case, deserves to get banned temporarily at a minimum, and permanently in most cases.