database_rules.json

{
   "rules": {
      ".read": "root.child('profiles/researchers').child(auth.uid).val() === true",
      ".write": false,
      "control": {
         		"groups": {
           ".read": "auth != null",
           ".write": "auth != null"
         }
      },
      "ffq": {
         "$user": {
            ".read": "auth.uid === $user",
            ".write": "auth.uid === $user"
         }
      },
      "survey": {
         "$user": {
            ".read": "auth.uid === $user",
            ".write": "auth.uid === $user"
         }
      }, 
      "feedback": {
         "$user": {
            ".read": "auth.uid === $user",
            ".write": "auth.uid === $user"
         }
      }, 
        "profiles": {
         "$user": {
            ".read": "root.child('profiles/researchers').child(auth.uid).val() === true",
            ".write": false
         }
      },
      "reports": {
         "$user": {
            ".read": "auth.uid === $user",
            ".write": "auth.uid === $user"
         }
      },
      "config": {
         ".read": true,
         ".write": false
      },
      "users": {
        ".write": "root.child('profiles/researchers').child(auth.uid).val() === true",
         "$user": {
            ".read": "auth.uid === $user",
            ".write": "auth.uid === $user"
         }
      }
   }
}