title: When the same user ID is trying to log in on multiple devices, how do I kill the session on the other device?
body: <p>What I want to do is to limit a user ID to only being able to log in to one device at a time.  For example, user ID "abc" logs in to their computer.  User ID "abc" now tries to log in from their phone.  What I want to happen is to kill the session on their computer.</p>
  
  <p>The Spotify app does exactly this- Spotify only allows one User ID to be logged in on one device at a time.</p>
  
  <p>I'm using ASP.NET membership (SqlMembershipProvider) and Forms Authentication.</p>
  
  <p>I've experimented with Session variables but I'm not sure exactly where to go from here.</p>