Rob wrote:The best thing to do is to put a question in the register page, and change it every so often, e.g. "what's the name of this forum?" or "who made code lyoko?" etc. Bots will never be able to get past that unless whoever codes them takes the time to update their bot every time the question is changed.
As good idea as that is, we're trying to keep things admin wise (not too much work). That is kind of predictable, yet strong. Bruteforce could get past it though. And before I conclude, I just wanted to tell you PHPBB isn't all that handy when it comes down to specific details.