title: Firebase rules write/read
body: <p>If i write <code>write: "auth != null"</code> who can write ? </p>
  
  <p>Only the person which has my google account and password or all persons who have a google account?
  I want to be the only one who can write to the database page but I can't change the rule to false.</p>
  
  <p>If I write: <code>".write": "auth != null"</code> who can write to my database?</p>