Here's a Daily Kos alum. Nobody knows who he really is. Here's a discussion of who he is. Read the comment thread.
Here's kind of an uberdiscussion of our topic. Read that comment thread. And it links to this.
Anonymity (including pseudonymity) does much good online. It also allows bad things to happen, but so does free speech. Before we tinker with the defaults, we ought to at least recognize what we may be giving up in the realms of (1) the political, (2) the social, and (3) the personal.
1. Anonymity allows people to say and do things that those in power don't like. It enables dissidents to speak and whistleblowers to blow their whistles.
2. Anonymity allows people to say and learn about things from which social conventions otherwise would bar them. It helps a confused teen explore gender issues.
3. Anonymity (and especially pseudonymity) enables a type of playing with our selves (yes, I know what I just said) that may turn out to be transformative of culture and society.
Anonymity also allows some awful things to happen more easily, but we can't fairly decide what we want to do about it unless we also acknowledge its benefits. Just as with free speech