Link to Original Source
From the letter: 'Here's the deal, Mr. Gates: Either Microsoft undertakes dramatic, real steps, through its marketing, wholesale, and retail operations to assure that Halo 3 is not sold, via the Internet and in stores, directly to anyone under 17, or I shall proceed to make sure that Microsoft is held to that standard by appropriate legal means. I have done that before successfully as to Best Buy, and I shall do so again as to Microsoft and all retailers of Halo 3.'
So, the question is: Why go after Microsoft and not retailers as he's done 'successfully' before?"
(Private Credentials are a cool PKI replacement and anonymous ecash tech that allows you to prove certified attributes like age, credit rating, group membership, etc without revealing who you are; to allow you to have a digital life without the digital dossier effect inherent in central databases like google's).
Following that Adam Back announced — credlib, an open source implementation of Brands credentials (and the older more basic Chaum certificates).
Relates to recent news from IBM's Zurich labs on their identity-mixer project (reported on slashdot here) that is based on the less efficient Jan Camenisch and Anna Lysyanskaya credentials."