Chris Jones has a new post to his OTN blog today pointing to two new articles by Eli White about managing malicious website use:
The techniques Eli covers will always be applicable in one form or another. They should be a fundamental part of any website architect's bag of tricks.
The first article focuses more on methods for preventing and dealing with the inevitable spamming that comes with running a larger site. Eli's experience at Digg has provided him with recommendations like creating hurdles for spammers to get past and evaluating the content (services like Defensio or Akismet are useful for this).
The second article talks about something a bit harder to deal with - when users "game the system" and find the loopholes. His recommendations to combat this sort of abuse include rate limiting, pattern matching and leaving "traps" by tracking user usage.