We're not alone here on OlyBlog in dealing with the issue of how to moderate discussion.

Calculated Risk:

I cannot make anyone stop responding to pointless or nuisance comments. You have to want to restrain yourself, because you understand that the only way to get rid of them is to fail to give them the attention they want. A "troll" is not just someone whose comments you disagree with, or even just a nasty or badly-worded comment. A troll is someone who does not, under any possible set of circumstances, care what you think about him or his comments. He merely wants attention. Negative attention will do. The more you disagree with him, the more he is able to tell himself that he is persecuted and victimized or the only voice of reason or one of the elite few who has the God's-eye view of the world or whatever his current delusion is. If he isn't merely a narcissist who thrives on feeling attacked, he's just some putz who enjoys irritating other people. Therefore, you "feed" the troll by paying any attention to him at all. It does not matter what you say in response. Any response to a troll just encourages the troll.

Besides classic trolls, we have a few resident long-winded bores who believe that the rest of us have never been exposed to some trite, shallow, bombastic rant they just heard on the radio or read in Reader's Digest or saw in a vision, and feel compelled to share with the rest of us. These people lack any possible sense of context or audience; they are incapable of noticing that the bulk of our commenting community has been exposed to the world for a while now and is not interested in any comment that starts "there is one simple answer to this the rest of you aren't getting." It does you no good to respond to this type either; they'll just re-write the same comment again, at the same length, saying the same thing, until you "get it." They are bores with no self-awareness. The cool thing about the internet is that you can just scroll down to the next comment without being "rude." So take advantage of the medium.

Absolutely none of this is to say or imply that you are not invited to debate with each other or to correct misstatements of fact. You are also still allowed to make jokes and ramble occasionally and even from time to time introduce a new topic that is relevant. Most of you are grownups who understand intuitively where the line is, and if you cross it now and again you catch yourself and go on mostly behaving yourself. A few of you are those problem children who are not capable of taking only one cookie or talking quietly in the library or waiting until it's your turn and you ruin all group experiences for everyone else. You goad the authorities into instituting draconian rules for everybody in order to prevent you from getting out of control. You are probably going to be like this for the rest of your life, since such behavior patterns that persist past puberty usually don't go away. All I can say to you is that you really will get nowhere asking me personally to validate your feelings or demands. If you worked for me, I would foist you off on another department or just fire you immediately. I learned a long time ago that I can't fix you and I can't function with you and you need me a whole hell of lot more than I need you. Of course you don't recognize yourself in this description. That'd be your big problem. I'm really just writing this to once again remind your fellows that I am not trying to inhibit anyone having a good time in the comments. I am trying to inhibit those of you with no judgment and no ability to control yourselves.

This analysis supports the conclusion that I've come to, which is that the crucial factor comes down to whether the problem commenter cares what others think, and can adjust his/her communication style.