I have no anecdote or any paper siting, but the reverse isn’t always true either. Just because you’ve been given a real name, it doesnt actually prove that they are that person until you go much MUCH deeper to verify the validity of that person via several sources. So you can be equally swindled via avatar or real. It’s all a matter and degree of trust and accountability you can assign to the identity given, even in a physical meeting situation.

Yes, forming an online identity is vastly simpler than setting one up in the real world. But as you mentioned, at some point, with the advent of searching and aggregation mechanisms, you should be able to piece together a coherent picture of that online identity as an individual even if it never resolves to a physical person and it can serve as enough information to establish that trust and accountability.

In the end it’s a matter of being able to hold an identity to accountability to an extent that will give your rights protection. We may not be there yet with online identities, but there can be exceptions made to link identities to accountability. Most often this comes in the form of releasing the online identity’s creator information so that real world law can be applied to them, but perhaps in the future, there can be a certain amount of accountability and thus caution towards consequences that can be leveraged onto online identities that would be as real to them as it would be in the real world. How? That I’m not sure yet. But at some point we’ll reach a proliferation of online personas and time/effort investment into your identity that it would be a genuine loss to have action take against that identity.

Imaging having your email address/domain banned. Something that you’ve been using for decade(s). With the disappearance of that identity, you could lose quite a lot of your online persona in terms of things like blog reputation, paypal account, ebay ratings, forum posts and so on. Interesting times to see how all these will stick with people in the future.