title: how to detect if user is logged in to site from another browser?
body: <p>Scenario:</p>
  
  <p>User logs into website.com using firefox. Login credentials are valid, user is directed to member's page.</p>
  
  <p>User tries to log in to website.com using chrome. Login credentials are valid, because use is already logged in using firefox, system will throw error, asks user to close other session to login through chrome.</p>
  
  <p>How can I detect that? Right now I am able to detect it if user only use one browser, but seems to break when user uses two different browsers to log in at different times.</p>
  
  <p>EDIT* I want to say it's more than just using different browsers, the website should not allow multiple people to log in with the same login credentials.</p>