How to manage users after logging them in with google auth

Hey I'm using google auth to login users to my site. What I wanna do is check if user has been banned or something.

I know I can store user's email and then check if that emails been banned if he logs in next time. Is there any better way of doing it?

I'm not a google api user, but have you check the documentation before asking?

Email from profile info - best way to identify google user. Access token will be changed on next login.

Just 'json_decode' received data from /o/oauth2/token and use ['email'] field of returned array.