Yeah! Persona sets `.backend` too, which is where I got this idea. The default auth thing doesn't, so we would have to do something like `getattr(request.user, 'backend', None)`, but we can use this to test if a user signed in with a token or with the login form. Also, if the user is logged in, and clicks a link with a auth token, since I added the `if request.user.is_authenticated()` check, it won't change `request.user.backend.`.