public static function isXDomainUser($uid)
	{
		$db = \App::get('db');

		$query = 'SELECT uidNumber FROM `#__xdomain_users` WHERE #__xdomain_users.uidNumber=' . $db->quote($uid);

		$db->setQuery($query);

		$result = $db->loadObject();

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

		return true;
	}