Sharing data between OpenID's the Google Docs way?

What is the best way to share data between different openid's based on email account. E.g.

1. User1 log in to mysite with OpenID
2. Create some data
3. Hit 'Share with' and put in email开发者_如何学Python adresse of User2
4. User2 log into mysite with OpenID (related to the email User1 provided)
5. User2 access data created by User1

Can this be done reliable?

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It would be a a bad idea to depend on the email address provided by openid, because an use can input provide anything as an email and it isn't verified in any way (so you'd need to do that yourself).

Other than that, the question isn't related to openid at all, since it doesn't store any data. Store it in a database, or something -- it's no different than storing user's data without openid.