Reading Firebase data returns client error despite rule being "true"

I am trying to figure out how to do a simple CRUD with angular + firebase. I started with a read operation. I have the following data structure:

With this in mind, I created the following rules:

I have a working factory like this:

factory('wordsFactory', function($http){
  var factory = {};
  var words = [
    {content:"hi", definition:"ooo"},
    {content:"h3", definition:"ooo222"}
  ];
  factory.getWords = function(){
    return words;
    //ajax call here
  };
  factory.addWords = function(){
    //something
  }
  return factory;
})

      

        
        
        
      

    

I changed it to try and include a call like this:

factory('wordsFactory', function($http){
  var factory = {};
  var words = [];
  var ref = new Firebase('https://my-firebase.firebaseio.com/words');
    ref.once('value', function($scope, snapshot) {
        $scope.variable = snapshot.val();
        words = [
          {content: ref.content, definition: ref.definition}
        ];
  });
  factory.getWords = function(){
    return words;
    //ajax call here
  };
  factory.addWords = function(){
    //something
  }
  return factory;
})

      

        
        
        
      

    

However, when I try to read, I get:

Error: permission_denied: Client doesn't have permission to access the desired data.

and

FIREBASE WARNING: Exception was thrown by user callback. TypeError: Cannot read property 'val' of undefined

Several things, I understand that due to what I have, even if it works, it will only return one value. I'm fine because I just want to figure out how to make it work. I also know that my current data structure could be greatly improved, again I just did this to learn, but feel free to suggest anything you think might help me.

My main problem right now is that I cannot read it. I should also mention that the factory works correctly without firebase, it gets called in the main controller.