public static function paranoid($string, $allowed = array())
	{
		$allow = null;
		if (!empty($allowed))
		{
			foreach ($allowed as $value)
			{
				$allow .= "\\$value";
			}
		}

		if (!is_array($string))
		{
			return preg_replace("/[^{$allow}a-zA-Z0-9]/", '', $string);
		}

		$cleaned = array();
		foreach ($string as $key => $clean)
		{
			$cleaned[$key] = preg_replace("/[^{$allow}a-zA-Z0-9]/", '', $clean);
		}

		return $cleaned;
	}