KEVIN'S LAW. Kevin Drum proposes a new principle of net-based discourse: "If you're forced to rely on random blog commenters to make a point about the prevalence of some form or another of disagreeable behavior, you've pretty much made exactly the opposite point."
For illustration, see the peerless K-Lo digging random stuff up off Democratic Underground and the dKos diaries. I'd say if you're looking at a Scoop site, then something that gets promoted to the front page or otherwise featured by the relevant people is fair game, but an open diary section is like a comment thread -- an unfiltered place where anyone can post. Again, if these are the best examples you can find of the behavior you're criticizing, the moral of the story is that the behavior is rare. Keep in mind that there are 300 million people in the United States which ensure you can always find someone saying or doing just about anything.