I get this in the log file:
9/6/2011 12:51:22 PM -> Can't open group file : ./default/./Text_Files/admin1.txt
9/6/2011 12:51:22 PM -> Can't open group file : ./default/./Text_Files/admin2.txt
Just so you know, IP is "open" to everyone because when you try to join a server, even if you don't have its password, you must contact it first, so your PC will contact a server by its IP address. But having an IP address doesn't mean anything at all. In fact, if someone knows how to attack your server, getting your IP address is the easiest thing tbh.
Anyway, I don't believe there's anything you can do about it. In fact, not even PayPal could do anything when Anons attacked them (after Wikileak got taken down - google it), simply because the server would hang up after so many requests from so many different computers. And we are talking about such a big company as PayPal, so in a BR connection it would be even worse, as we all know our infrastructure sucks. Not to mention your firewall must be useless...
That video is from 2007, I believe Scawen has already fixed it, so no need to bring this up and that is why shorty943 could not trace to that IP.
Btw, I'm not an expert in networks, so what I said can be wrong.