From Ward's Wiki:

Q: Why can't we use NickNames instead?

A: In general, it is observed that people who use online nicknames care less about what they write. The discussion is usually taken more seriously when people do not use NickNames, but use their real name

As a courtesy, I'd like to ask anyone commenting on this site to leave their real name with the comment. That is, unless you're someone I've known online for so long under an alias that I wouldn't recognise your real name, or if you honestly (and publicly) identify with your adopted name more than your given name.

I reserve the right to treat anonymous comments with contempt. By its nature, a weblog is a form of personal conversation: I can't help but disclose my own identity with every word I write, so I ask that you have the courage of your convictions and own up to your words as well.

Thank-you very much. Have a nice day.

(Further discussion almost a year later: On Comments)