title: How safe is auth !== null? Firebase
body: <p>I've been using Firebase for quite some time, but I only now decided to really look into the security rules. </p>
  
  <p>My question is, how safe is "auth !== null"? Yes, I realize that this means that only an authenticated user can access the data, but how easy is it to become authenticated? Can someone sign up for the app, and then use those credentials to GET request right into my database?</p>
  
  <p>Like I said, I'm new to Security rules, so I'm sorry if this is an obvious question.</p>
  
  <p>Here's my security rules:</p>
  
  <pre><code>{
    "rules": {
      "Users": {
        "$user_id": {
          ".write": "$user_id === auth.uid",  
          ".read" : "auth !== null",
          "shoofers" : {
            ".write" : "auth != null"
          }
        }
      }
    }
  }
  </code></pre>
  
  <p>Thanks!</p>
  
  <p>Neil</p>