Maybe required registration to post?
If it keeps coming registration with approval.
Thats just it.... they are posting under a guest status, which I have turned off, but for some reason they are still getting posts in.
There was a member that tried signing up with the same IP, we have a e-mail validation process and they never validated the account to use it to post.
I would hate to make member sign up be approved by a administrator or moderator, this would take a little bit of time to get the accounts approved and I think it would hamper new members from actually signing up then posting.
I believe this is actually a bot doing this, if it wasn't the links they are posting would actually work, but they don't.
There is a security update / patch for our version of software, I need to get it installed soon, maybe tonight.
Hopefully that will stop this from happening again.