Well, he got quite a number of warnings in the past, (before he was gone for 4 days). He came back, and was behaving himself for about a week, and then he started spamming everywhere again.

For instance, posting in battle.net hacking section saying "dont use tradehack it is not supported by blizzard".

I think he should be banned for several days, just like what we've done to kuja that time. Or stealth him. A perm ban would be too harsh, I agree.