Where no one can be sure of the (logically irrelevant) RL privileges that the person behind a persistent pseud might bring to a debate, participants have to focus on what was said, and come to grips with that, rather than dismiss some speakers as being unworthy of their full notice and consideration.

Or else question or assert about privilege instead/in addition to the topic being debated, and thus indicate (at best)that they find that context relevant or (at worst) they aren't capable of debating ideas on their own merits without playing on privilege dynamics.

phoebe_zeitgeist, that's a great point.

You might consider adding it to the Geek feminism Wiki list of who is harmed by a Real Name policy -- the link from "vulnerable populations" in Syne's post points there.