Forum banning certain words and phrases from being posted
 

I seem to have a spammer that keeps changing his IP to post the same BS every few days. He's not some asian spam bot using a proxy, he is using a Canadian ISP and simply forces a new IP every time he reregisters. I don't want to ban his IP range because there are quite a few other Canadians that may be using his ISP since my forum is largely Canadian.

How can I ban certain words and phrases so this dimwit is forced to manually retype every post?


Thanks.