In the Who Owns "You" panel at Supernova (available on IT Conversations) the question came up about eBay reputation. An eBay seller's reputation score is calculated from how other eBay users rate the seller. Does that score belong to the seller, the eBay users who contributed to it, or eBay?

Pretty easy actually, when you consider the principles of reputation.

• The eBay score is eBay's story about the user. They calculate that story and it's pretty simple but still they're the ones deciding the algorithm that's used.
• The eBay users and eBay jointly own the ratings. That is, each user should have the right to use in any way they want all of the ratings they've contributed. Of course, so does eBay.
• The seller jointly owns, with the buyer data about the transactions that he or she had with each buyer. Both parties should be able to use that data in any way they see fit.
• In the interest of transparency, the eBay seller ought to also have the ability to inspect, but not change any rating about them.

Now, what should be and what is are two different things. Right now, there's no convenient way to export your transactions or ratings from eBay. eBay considers that a key part of their business model. Internet-scale identity systems however, will invariably give rise to cross-site reputation. Something I think will have a big impact on the 'Net.