pretty much 100% of forum spam is done by automated bots, with fake email addresses and disposable IPs.. its all done just to get the linked sites ranking higher in search engines, so posting the forum spammer info wouldn't really be much of a threat to them
the best method i've seen so far for spam revenge was the recent carpet cleaning people episode.. although you can report sites for spamming, if you're inclined to do that kind of thing
