public static function find_by_user_id($user_id = null)
	{
		if (empty($user_id))
		{
			return false;
		}

		$l = self::blank()->getTableName();
		$d = Domain::blank()->getTableName();

		$results = self::all()
			->select($l . '.*')
			->select($d . '.authenticator', 'auth_domain_name')
			->join($d, $d . '.id', $l . '.auth_domain_id', 'inner')
			->whereEquals($l . '.user_id', $user_id)
			->rows();

		if (empty($results))
		{
			return false;
		}

		return $results->toArray();
	}