That has to be the dumbest comment i have seen in a long time.
Firstly, he would need to have the attackers REAL ip numbers to contact their ISP and then he would need proof that they initiated a ddos attack. Any idiot nowadays can create a C++ ddos bot and have it infect pc's and run a botnet on IRC. Proving it is slightly harder.
Best way is just ride it out, as most of the infected host machines or the few machines will be set to hit you with mostly a UDP attack for a certain period of time. Or if you know what your doing, then log their ip numbers and hit them back harder.
I don't condone DDOS in any way shape or form, as for me it's just skiddies who are using other peoples hard work.
Funny, this is the dumbest reply I've seen in a long time.
If he knows it's "butthurt" gamers who are doing it, he'll have their handles, which if the game server has decent logging will be able to be linked to their IP address which the police can then use to trace back to the individuals involved.
Proving it was those people who initiated the attack however is a different story.
Also giving the advice of logging their IPs and hitting them back harder probably isn't the best idea, especially when you then go on to advise you don't condone it?