title: Logging out from facebook when using MVC 5 OWIN
body: <p>I have an MVC 5 web app that has facebook authentication set up and working nicely. User clicks "Facebook" on the login page, signs in to Facebook and that authenticates with our web site. If the user logs out, the call to AuthenticationManager.SignOut() logs out of the web site correctly, but if the user then goes back to the login page and clicks "Facebook" again they are immediately signed in without having to sign in to facebook.</p>
  
  <p>So my question is, how do I configure MVC 5 OWIN facebook login so that the user is signed out of facebook when they sign out of the web site, or to put it another way, prevent caching of the authentication for the next sign in. I don't want a users facebook login to be silently cached in case they are sharing a browser with other users.</p>