The debate forum has recently been attacked by a phpbb spammer known as Pepotamo1985. The forum had one subforum that was open to anonymous posters. (BTW, I like to call it a subforum, instead of overloading the term forum.) And that subforum was getting spammed at least once a day with porn site ads.
For a temporary fix, I closed the subforum to anonymous posts, but I needed a long-term solution. No mods existed to deter the spambots, so I decided to write one myself.
The solution I implemented is what I use in stopping spambots on my blog comments. On my statistics page, one can see that spambots really love my blog. But, I rarely get any spambot comments. As a matter of fact, I don’t remember any spambot comments.
So, I put together a mod and released it to phpbb.com that is called Anti-bot Guest Post Mod. And it seems to be working. I haven’t gotten any spambot posts in the past day. You can try it out for yourself on this test topic.