Saw this come up on slashdot, thought it would be a good way for Brian/The Mods to deal with the trolls.
Level 1: The Cave. Put trolls in the box, so they can see everyone and respond, but their comments aren't actually published, so no one sees them. Give them the silent treatment.
Level 2: Misery. Active aggravation. Cause 403, 404 errors, fail form submit, random blank pages, randomly go to the wrong node. My favorite: crash IE6.