title: WIF won't work with ASP.NET MVC 4
body: <p>I have Windows Identity Foundation working well with MVC 3. However, in MVC 4 it seems WIF doesn't get a chance to handle the Not Authorized response and redirect to the STS - instead I get redirected to login.aspx, which is good old forms auth. </p>
  
  <p>In MVC 3 I used to disable forms auth in web.config, but it doesn't work in MVC 4.</p>
  
  <p>I know there have been changes to authentication and authorization in MVC 4, but my Google skills seem to have deserted me and I can't seem to find out how to stop forms auth interfering. Any pointers?</p>