title: MVC 4 OAuth - How to prevent unauthorized users?
body: <p>Folks,</p>
  
  <p>I just moved to VS 2012 from VS 2010. I am still figuring out the new SimpleMembershipProvider and OAuth provider.</p>
  
  <p>After creating a default "Internet" project, I enabled Google client. It seems now I can login using either local username/password or Google authentication.</p>
  
  <p>I would appreciate it if someone can help me understand the following:</p>
  
  <ol>
  <li><p>I would like only authorized users to login. It seems any Google user is able to login at the moment. How do I prevent this?</p></li>
  <li><p>I would like to set it up such that although anyone can request for "registration," only admins will decide who is allowed to access the system. How can I achieve this?</p></li>
  <li><p>Is there a way to completely get rid of local username/password and just use Google authentication instead?</p></li>
  </ol>
  
  <p>Thank you in advance for your help.</p>
  
  <p>Regards,<br>
  Peter </p>