{
  "rules": {
    "secretnode": {
      //only an admin user can read
      ".read": "auth != null && root.child('adminusers/' + auth.uid).exists()"
    },
    "adminusers": {
        ".read": false,
        ".write": false
    },
    "othernodes": {
        ".read": true,
        ".write": true
    }
  }
}