Are you sure it's not a bot? What's your forum software? Do you have any kind of spam prevention?
If he/she is a "human", add some words of his URL/URLs to the invalid words list of your forum.
You can't do anything against a spammer (not a bot) but delete the posts once and again. Finally you'll win the battle; be patient.
[edited by: Lexur at 6:41 am (utc) on Dec. 27, 2006]
How about leaving his posts online but edit the Links to point to one of his competitors, or to one of your favorite sites.
Perhaps its this guy:
This sounds like a bot. I have had this happen before. With Vbulletin and phpbb there are many effective mods to stop him, if the board software you are using has NO anti-bot mods and you don't have the skill to write one, consider switching to one that does.
Do you have email verification for signup/registration? That solved 99% of my spam problems.
I believe it's a human, he has his own search string in google going on and when i first checked his ip it was from AOL. And i'm using invision power board.
One good way to deal with persistent problem members is to change your methods each time. Ban him one time, block his IP the next time, put him on universal ignore after that, etc. You will outlast him, and, if you are lucky, you will get him to waste a bunch of time trying to post, or posting messages that nobody sees.
A multi-detector system that uses a non-obvious cookie is one handy tool to spot these clowns before they make their first post with a new ID.
If your board is in the up to date period with invision contact them. IPB isn't a free forum and they can likely point you in the right direction be it with a mod or with forum setup to block this.
Then again, he's on your forum not mine, don't chase him off too fast or he might end up on mine, lol. Keep a smile about it whatever you do, he can't win this fight.
don't allow posters to include links until X number of posts