When you block a player, it's YOU who won't see servers he's playing on.
He will still see your server and be able to join it. It is not a permanent ban for someone and I haven't heard of a way to do it.
Unless something changed in this regard very recently but I doubt it.
dunoo lam i've added a few ppl to my block list and never seen them join again so dunoo might of got lucky
i will try that block thing, might be helpfull 8))
8)) clan is the answer
fallow the rusher