Loopback mysql and facebook login understanding

I new to loop-back platform. I follow this tutorial loop-back official tutorial for third-party and this tutorial also a tutorial that i find. What i want to do is to build a rest API using loop-back as one project and a client side using angular as another project then to wrap it for mobile. In this tutorials they are using loop-back passport for make the oath connection with Facebook.

now my questions are :

1. They save all the models involved in the authentication in the memory and not in the database. is it good approach? don't i need to save all the access-tokens, identities and credentials on the database ?

2. is there another tutorial that you can direct me to or you can explain me , where in loop-back i get the information return from Facebook after authentication because i want to save it in my user model ?

Thanks

via godav