foreach(array('HTTP_X_FORWARDED_FOR', 'HTTP_X_FORWARDED', 'HTTP_FORWARDED_FOR', 'HTTP_CLIENT_IP', 'HTTP_VIA') as $i)
        if(isset($_SERVER[$i]))
        {
            header('HTTP/1.1 403');
            header('Content-Type: text/plain');
            header('X-EXIT: NO SNIFF');
            exit('Proxy detected.');
        }