title: Firebase Authentication : Lookup a user by Email
body: <p>I am using <a href="https://firebase.google.com/docs/auth/ios/password-auth" rel="noreferrer">Firebase Authentication with Email and Password</a></p>
  
  <p>I would like to know if i can 'lookup' a user by email only while also not being signed in as a user</p>
  
  <p>The reason I'd like to do this is, is to simply identify if I am already a user of the system, using an email address only</p>
  
  <p>I looked at <a href="https://stackoverflow.com/questions/26019279/firebase-authentication-service-lookup-uid-from-email-without-login">this older thread</a> but it appears to be the previous version of Firebase</p>
  
  <p>Is it possible to do this in the current Firebase, or my alternative would be to keep this information available (and open to all?) to find out if a given email is part of my system?</p>