Matt Blumberg is worried about BLAM. I think that if he follows the money, then he’ll see that most blam is an attempt to garner PageRank. Remove the motivation and you’ll minimize the bad behavior.
*Knock on Wood* I haven’t experienced a blam problem here at Take the First Step. I attribute that to clean living and rank stripped trackback and comments. Like Matt, I have a lot of misgivings about blacklists. I’d prefer to have comments stripped of rank transference, moderation to enable transference if appropriate, and whitelists to minimize the moderation load. And blacklists only if all that fails.
So far, step one is good enough for me.