On my forum, a lot of spammers keep registering spam accounts. They don't post anything in their signatures, but they do attempt to post spam on my site. How can I prevent that?
My forum version is 3.5.0.
I had the same problem and I solved it with a combination of:
re-Captcha for registrations
StopForumSpam mod
Akismet
Can't be sure which of them is doing the best work, but the combination of them had a 100% success.