It's only a matter of time...
... before websites don't even need to know your name, they'll be able to infer your identity from all the other information that's been collected on you over time. Unless we poison the well while there's still time, which is what I hope is what's motivating at least some of the pseudonymous subversion.
Once the false identities are out there, it's amazing how persistent they are. I've been getting insurance quotes addressed to Mr. E. Shopper for years now. Years ago, we set up a fake employee, complete with a DDI and write-only answering service, to whom all unsolicited sales calls were routed. He still gets the occasional e-mail, though the phone calls did eventually dry up...