I don't think it's a matter of if you're serious. I think it's a matter of "Do you want to be known?"
Or rather, "Under what name would you like to be known as?"
I say that because David Copperfield is just a stage name. Which brings up the question: How different is a stage name from a username? Ignoring the fact that usernames are often weird (include numbers, for example), do they not both stand in for a person's real name, replacing it under certain circumstances? This is something very popular among musicians, as well as some writers, and even actors (Dwayne Johnson originally even using his stage name of The Rock (carried over from wrestling) while performing in movies for the longest time, comes to mind).
I suppose the difference is that with musicians and actors (and even David Copperfield), the stage name is still tied to the person--they aren't anonymous, as their face is tied to the name (at the very least).
Thus, the real issue seems more to be the anonymity. Which brings up yet another question: Is using your name not only necessary, but also sufficient? I'd definitely say that using a name that you would like to be known as is necessary (it doesn't have to be your real name, as a stage name would work just fine). However, I'd say it's far from sufficient. What does it matter if I'm John Smith or That Canadian Guy (which is actually a real comedian's stage name, who is fairly well known--can you guess why he chose that stage name? (answer: Because that's the thing that sticks with most people, so he just adopted it as his stage name))? Unless you can tie a real person in with the name, then it's just a name. It could just be random numbers and letters, it serves the same person--it identifies the speaker. It still doesn't say anything about the speaker though. It doesn't give any substance to the speaker (well, typer). The speaker is still an anonymous person, even if using their real name, the only difference is that their name sounds more...real.
So where could one go from there? Possibly adding a picture of the real person (dressed up in whatever it is their character wears; Draven (I hope I spelled that correctly, or got his name right, rather, heh) would be a good example) as their display picture. Having a face to go with a name makes it a little bit more of a...human interaction. And takes away a bit of the anonymity, which is what I would target as the real culprit that should be addressed.
But yeah, going by one's real name (or stage name) is definitely a good start (keyword: start).