There is no substitute, no magic bullet, to replace active moderation. One tip used by larger forums with multiple subforums is to assign mods to a single subforum. Warn and ban as they see fit. The "blanket statement" line is also a non-starter. It's human nature to group people. How would a politician feel if he visited some of the subforums? Teachers? Union members? The top thread in the GF forum right now is a thread comparing union workers to a Ruger recall. They don't work and you can't fire them.
Yup