Open Social API docs are online
code.google.com
code.google.com
That's great. I can do all the programming work, the users can do all the work of setting up their social network, and Google can keep all of our data for us. Gee. What a deal.
http://{domain}/feeds/people/{user-id}
Notice that "domain" is a variable. In any case, why would you worry about Google being able to store data that is publicly accessible through a standardized API?