Recently spambots are attacking forums at increasing rate, maybe we should get some captcha module or something similar?
We do already have a ‘captcha’, but it’s so simple that anyone could train a neural network to break it.
It’s also unfortunately widely used, which motivates spammers to write code to defeat it. The ideal captcha is custom-written for each application, so that there is little benefit for someone to write a defeating program.
Ironically, the captcha on this site was originally custom-written by Josh Yelon, to replace the default phpbb captcha that was widely used and therefore easily defeated. For a time, this was the only site that used Josh’s new captcha, and during that time it was 100% effective. Unfortunately, Josh also published the captcha on a phpbb forum, and many other sites adopted it for their own use; so it is therefore now considerably less effective.