Facebook data storage policy clarification

Question

I want to create a "Login through Facebook" on a website using Graph API like Stack Overflow does.

Once you login to StackOverflow through Facebook for the first time ( If you have an account in Stack Overflow using the email address same as the Facebook email, stack overflow will log you in to that account ) it will create an account for you in stack overflow automatically. This process extracts email address and full name from your facebook account and stores it in its database.

My question is Does Facebook data storage policy allow this?

http://developers.facebook.com/policy/#data

Answer 1

I would imagine the following:

Users give you their basic account information when they connect with your application. For all other data, you must obtain explicit consent from the user who provided the data to us before using it for any purpose other than displaying it back to the user on your application. A user’s friends’ data can only be used in the context of the user’s experience on your application.

Covers the specific usage of sites like StackOverflow. E-mail address, name, etc. of the user probably falls under "basic account information". The data storage policies are probably more intended for data from friends, or Facebook specific data like wall posts, pictures, etc.

Answer 2

You can do this, yes. As a not, simple Facebook connect does not provide the users email address, you have to explicitly state that you want the email permission - the permissions API page has more detail on this.