Given a choice between anonymous bloggers (and commenters) and those who sign their real names, I prefer to deal with those who use their real names. In part, this is because I admire their willingness to stand behind what they say regardless of the possible consequences. I do understand that it's easy for a tenured Professor to say this but I've never hidden behind anonymity even when I was an undergraduate, a graduate student, a postdoc, or an untenured Professor.
Greg Laden discusses anonymous bloggers in Some of my best friends are pseudonymous bloggers. I pretty much agree with his position. His posting is well worth reading.
I also agree with his stance on arguing from authority. In the real world, it makes a difference if someone is someone is putting forth an argument based on years of experience in the field or not. Nobody has time to evaluate all of the facts on every issue. We have to learn who we can trust and who we can't. The connection between this and anonymous blogging is obvious.
Please do not interpret this as a blanket recommendation to trust everyone in a position of authority. Similarly, I'm well aware of the fact that non-experts often make insightful contributions to a debate. The issue is much more complex than that. We don't need to list all the exceptions to the general principle that wisdom and experience usually count for something.
[Cartoon Credits: (top)Anonymity and Sovreignty (bottom) Cerebral Kitchen Productions]