I've been working on the 'identity problem' for several years with the hubzilla project. We took a different approach and made identity 'nomadic' which means that if you're "Fred Flintstone" your identity isn't tied to [email protected] but could pop up as [email protected] and your friends wouldn't know or care. In the application you're Fred Flintstone, period. Our members tend to migrate to different sites all the time - keeping their friends and content and profiles and settings intact. These can be cloned to various places where you wish to maintain your identity, or you can load everything from a thumb drive if you get kicked off one site for bad behaviour. If your home site goes dead for an hour, no problem. Post from another. Again - your friends and your content remain intact. Your profile and online identity are exactly the same. The only thing that changed is what computer you use - which we don't really care about and neither should you. And that's how it should be.