Legal information for Site terms and conditions document

Sorry for the delayed response. This isn't a question we've been asked before

First off, the Facebook platform policies are on the following page, which are different than the main Facebook terms:
developers.facebook.com/policy/

Specifically, you'd be interested in the "II. Storing and Using Data You Receive From Us" section. If you read through it, there's no where that the data is stated to belong to Facebook. Per Facebook's privacy policies, that data actually belongs to the user, but is stored on Facebook.

The authentication popup dialog when a user clicks the Login With Facebook button actually has a link to Facebook's terms and shows the user what data is going to be imported. So, by doing that, the user is explicitly agreeing to Facebook's terms and allowing your application access to the user's own data stored on Facebook.

While it's definitely a good idea to have extra terms and policies laid out on your site, I don't know if you need an additional term for importing data. Facebook does have a method when setting up your Facebook application where you can include a link to your own privacy and terms URLs. Those URLs will be shown during the authentication process in addition to the link to Facebook's terms.

Hope that all explains, though I'm certainly not a lawyer either.

Alex