Cleaning up spam on semanticweb.org and on letopisi.ru have resulted in a little tutorial and a presentation I want to show.
Ok, so here is some advice that can alone improve your spam situation.
- Healthy community. If your wiki has enough users who care about the content, they will clean up the spam manually.
- Heuristics and little tricks. For example you can set the waiting period for all the newly-registered users. That will help because the majority of bots register and immediately write something
- Questy captcha instead of any other captcha
- If nothing helps use behavior analysis tool called AbuseFilter