title: MVC OWIN: Always require users to input credentials
body: <p>I'm doing an MVC application which includes a form.
  The form consists of a variable list of users (participants on a team).</p>
  
  <p>For each user I would like them fill out some information. If they are already registered they can chose to login through FB or Google+ and the system will retrieve information about them automatically.</p>
  
  <p>When the user logs in through e.g. Google, a cookie is saved on their computer. As long as the cookie is still active it will prevent any further credentials to be inputted as google will just accept the cookie and not prompt for credentials. This will prevent other users (team members) to use this service.</p>
  
  <p>Is it possible to force external login providers to ALWAYS require credentials (or perhaps a parameter which sets the expiry of the cookie).</p>
  
  <p>Thanks in advance.
  Frederik</p>