I alerted the FBI a few years ago when I found an IRC botnet the same way you did. I talked to an FBI agent at the time and he took all the info. Amazingly the irc operators for the irc network couldn't care less and basically went off saying I should not have got infected in the first place(which I didn't). It sure seemed like they were all 10 year olds in the admin channel for the irc network. The irc channel was shutdown after a month or so but I don't know if that was just because the botnet moved to another channel or if the FBI did something.
