1) The guy in charge of network security at Valve isn't worth a nickel in salary.
2) Gabe Newell really has no fucking clue. Sure Gabe, piss everyone off by chanting September 30th as if it was a Divine Mantra for Enlightenment, only to tell the entire community "Fuck you, you WILL use our shitty delivery system if you want to play", followed by "Fuck you again, it's not done yet, so September 30th ain't happening", a week before that supposedly sacrosanct date.
And now you want the community to HELP you track down some meany haxx0rs that trundled all over your pisspoor security? Something tells me it's not really going to happen.
Also, I'd really like to know exactly what Gabe expects the community to actually DO about this. If his firewall and sniffer logfiles don't show anything, how the fuck is some joe schmoe on IRC supposed to find out anything? Unless he's expecting the perp to be bragging about it (or will be, or has been bragging about it, take your pick), which seems unlikely, given the fact he / she / they seemed to know what they were doing.
But seriously, keystroke recorders? We figured out how to get rid of those in the early 90's, Valve...
Maybe it's a modder who doesn't want to wait any longer...
Creston