protected function _itemBelongsToUser($data, $where = false) {
        $userData = Garp_Auth::getInstance()->getUserData();
        $userId = $userData['id'];
        if (!array_key_exists('author_id', $data)) {
            if (!$where) {
                return false;
            }
            // fetch the record based on the given WHERE clause
            $row = $this->_model->fetchRow($where);
            if (!$row || !$row->author_id) {
                return false;
            }
            $data = $row->toArray();
        }
        return $userId == $data['author_id'];
    }