Don Marti writes about the idea of setting a Troll-bit on forum posts such that every reply would also be flagged.
I’ve been thinking about how to solve such issues for mailing lists. I think that the way to do this is to create a new list for every contentious topic and automatically subscribe everyone who posted to the thread after the messages that were flagged as being too far off-topic. After that time anyone who tries to post to the main list with a matching subject or a header indicating that the message is a reply to an off-topic message would have their message redirected to the new list – and they would be automatically subscribed.
This would keep the off-topic messages away from the main list and also serve as a minor dis-incentive for people to post to threads that start going off-topic as most people won’t want to be subscribed to the new list for off-topic messages.
However such messages would still be archived (in a different section) so if the moderator mis-classified a thread it could still be reviewed by other people.
Also when moderating such threads it would be interesting to experiment with consensus moderation of posts. If N subscribers of the list who post regularly use a web form to indicate that a certain post was too far off-topic and should spawn a new list then that could happen.
I agree with Joey Hess’ rant about forums, so solving a problem for forums is not of interest to me, but hacking on a list server is something that I would do if I had enough spare time.