title: checking if user is already logged in through cfloginuser
body: <p>I'm using cfloginuser as a security mechanism in my application to secure web service calls that are being made.</p>
  
  <p>One thing I would like to do is stop a second user from logging into the same account when they are already logged into another computer. Essentially what's happening, is that since both share the same username, the first one to login just gets kicked out as a logged in a user once the second login occurs.</p>
  
  <p>Is there anyway I can check if a particular username is already logged in, therefore not even allowing the second login to even authenticate? (You can only be logged into one computer at a time)</p>