Sony was denied P2P patents in England, which has the good sense to disallow patents for computer programs. In Sony's proposed invention a P2P user with a file could add personal comments about the file, such as rating, nickname, and email address. These comments would be added to all past comments. As the file was shared with others, it would build a history of such comments.

This kind of data is not supported by standard music metatags or current P2P protocols. So it would have to implemented with a custom network, custom client, or web service, which makes the most sense for persistent storage. Indeed there already is such a service called Bitzi that is already used by several P2P clients.

Sony is already working with P2P in a limited way by licensing its music to P2P customers of the UK Music ISP PlayLouder.