Wikipedia: Does Wikipedia use any automated text analyzers to filter spam or offensive content? - Quora
Sergey Z stashed this in engeneering
Thanks Tom Morris for the link to this anti-vandalism, anti-spam tool ClueBot:
I also want to investigate these tools mentioned by Daniel Kinzler:
Wikipedia uses the AbuseFilter extension extension. It's pretty elaborate, but the text filtering itself is done using regular expressions. There's also IP-Patrol (for the German Wikipedia) which uses SpamAssassin to detect spam.
Yep, I think this topic is pretty applicable to any site with community features.
It seems to be.
It seems like it's much harder to be successful enough to attract spam...
Than it is to fight the spam once you've attracted it. :)