I subscribe and read the feeds at digg. I mostly do it for the entertainment value in reading the various comments. digg is a place where people submit content and users (with some assistance from the omnipotent managers are digg) decide which submissions make it to the front page.
One thing that is very evident on digg is that if your comment goes against the, for the lack of a better phrase, the 'digg grain', your comment will be dugg down, big time.
Say, someone posts something 'positive' about ethanol or Senator Obama. After reading the article and then reading some of the posts you note a trend. For example, "Ethanol is good" or "Senator Obama will be different". But you, being the individualist that you are, call out some of these comments. Or god forbid, you offer an alternative point of view.
You will get dugg down. You are not agreeing with the majority, or at least the vocal minority, and therefore your point-of-view must be diminished. Who cares about improving the discussion? Who cares about facts? Who cares about the quality of comments? Nope, don't you dare go against the grain.
So for all the talk about free speech and democracy, none actually exists at digg. And it never will.