Quoting their homepage, At Zurker, … [y]ou don't just own your data, you own the network. Every Zurker user can very easily become a co-owner (future shareholder) of Zurker.
… and the loose, fishy details
1) 'Ownership' is not ownership. 'Ownership', in the terms of v-shares which they use to define the ownership that they offer to users, is not the same as actual company ownership. It is rather a share in equity – sort of like a corporate bond holder. A fine distinction, but not an owner, only a beneficiary.
2) No public monetization plan. Hosting data and services costs money. There is a list of who paid how much monetary support, but no plan available on how they plan to commercialize, especially when they claim not to own the data.
3) No data privacy agreement. Other than saying your data belongs to you, they do not state where your data is stored, who is allowed to view it, or who you should contact to delete it. If you haven't learnt from Klout's non-delete policy yet, … sigh. Then again, they're only in alpha, so it could just be too premature for monetization plans.
4) No mention of whose laws they follow. From what I can tell, Zurker Europe is run out of Belgrade, Ireland. But I can't find an address for them anywhere or any other information on the commercial entity behind this site. And worst of all, this information is only available after you sign up.
My profile is pretty public, and so I've gone ahead and registered with my public information. It is still invite only, but if, despite the warnings above, you do want to have an investigative look, go ahead here: http://www.zurker.eu/i-260279-ggxikdrwfe
ANY EMAIL, ANY PASSWORD. Zurker is currently in beta testing, and is not available to the general public without an invitation.