I think Declan's got the title wrong - Lessig's discussions that he references aren't about ending anonymity through escrowed pseudonymity - they're about replacing some True-Name-based or linkable applications with pseudonymous ones. For instance, one-use credit card numbers instead of regular numbers, which not only makes it harder for the merchant to do credit card fraud, but also makes it harder for marketers to trace your activities, even though they can go back to the credit card company and get that information. A similar application, which we'll unfortunately probably never see, is to replace the SSN with a pile of one-use tax ID numbers. That way, instead of giving everybody who needs to collect taxes on your account the same SSN, which they can then use to link lots of records together, you'd be giving each one a single number that only you and the IRS can coordinate. An application that people use all the time is disposable email addresses. Sure, you can use declan@well.com every time you give some web site your address or send email to somebody you haven't talked to before, but eventually spammers get that and it's too annoying; an alternative is to use free email accounts when you think you might get spammed. Hotmail was the canonical source, though yahoo's easier to use these days. One of Declan's fellow columnists, Annalee Newitz, uses a different username at her domain on each of her newspaper columns; presumably some of them become spam targets and get trashed eventually.