On another forum I use there is an ignore button. If there is a poster who continually makes junk, inflammatory or just plane trolling posts you can click into their profile and click an "ignore user" button and you no longer see any of their posts.
If enough people hit ignore on them they basically disappear from the forums and sooner or later they get that no one is seeing or responding to their posts at all. At that point they tend to simply drift away. It's a kind of community moderation and works really well.
DZ.com could really do with an ignore user button for some of the more persistent trolls, especially if it could be made sub-forum specific.