What, exactly, are the duties of the moderators?
Step in when it is necessary, after due consideration if it really is. Ideally, it will be a rare exception.
I really don't know what exactly the tools available to moderators are. I think you can delete posts, warn and ban users, move topics, etc.
The non-destructive options should always be first choice. Warn users rather than ban (the forum keeps track of warnings, so it helps us identify problem makers), and move rather than delete. But sometimes, like in the case of spam, the delete and ban options are appropriate.
