title: Multiple Authentication / Authorization support for Web API via OWIN
body: <p>I have a Web API project of ours that needs to be secured. I am planning to allow the user's that registered with my app to use the API [Forms Authentication], users with their own organizational accounts [ADFS] and Social Sign-In.</p>
  
  <p>I have all the middleware available to plug-in and make available to the user's. However, in my application I do have custom roles and privileges that are to be provided so that my application authorizes the service calls based on the existing privileges. What is the best way to accomplish this.</p>
  
  <p>I think that I will be required to provide my own custom implementation of the UserStore and UserManager with my own IUser Implementation.</p>
  
  <p>Kindly suggest the best practice for this scenario.</p>