I don't know if that's something to be worried about or not, but it just seems like common sense to try and cover your tracks if you are doing something that The Authorities don't approve of.
Sure, Tor might be broken (though there is no evidence of anyone getting in trouble for doing something through Tor), but it might also not be broken. We don't know. We do know for sure that when your IP address is 1.2.3.4 in the logs, they are going to call your 1.2.0.0/16's ISP and be on your doorstep in hours.
To be honest, I guess it's good for society that criminals are so stupid. The downside for me is that I don't get to read anything interesting when the media covers these stories -- all I get is "we got a bunch of IPs and people using their real names to harrass Sony executives' kids".
Use I2P. Just connect your IRC client to a certain port on localhost and you'll be rerouted to the I2P IRC server. If some government seized the I2P IRC server, nobody would still have any idea of who you are.
Follow-up lesson: turns out that random people on IRC are not automatically trustworthy.
Follow-up follow-up lesson: use Tor.