As I stated above, this guy generates hundreds of IP addresses, there is literally nothing that can be done to stop him since he can obtain IP's instantly from outside the IP range that was previously banned. The only way I know to do what he is doing is to have a premium VPN account, it must be costing him a few bucks to harass us.
*Rella, I'm gonna have to show you how to take a screen shot to show us what you are seeing from your end. Anyhow, we are all getting the same interrupt.
What I have seen from this guy is that he is able to post multiple entries under the same account name.
There is a gap of approximately 4 minutes between posts.
A routine that assures a new account cannot post more than 1 message every 30 minutes will take the charm right out of his efforts.
Placing a cookie in the browser will assure he has to clear his browser data every time he posts a new message
Placing a session variable in the browser will assure he has to open and close the browser every time he posts.
The above + an IP string comparison is approximately 4 lines of code in addition to some small data capture during the signup phase.
Net result is posting will become too much of a hassle to create new accounts and he is likely to move on to another board.
The alternative is you change the user signup settings of this board to "moderator approval" which is a standard feature in SMF
But then again you dont have access to the server, and you are told not to mess with the database, so whatever solution exists it cannot be executed.