I mostly enjoyed reading this book. The L33T speak was really annoying though. I'm sure hackers would use it. Since the author was in the tech industry he's probably right that the security professionals would use it, too.
I feel like if the author wanted to show how devastating such an attack could be he should have actually shown the affect the successful attacks had. We get a little bit of a look at the end but after all the dire warnings and pronouncements that even if they had the information they sought they couldn't stop it, it was pretty anti-climatic.
I also think it would have been good to acknowledge the other side, that allowing push technology has other problems. And giving the government too much control over the Internet isn't necessarily a good idea either.
I also think it might have been interesting to focus on government actors rather than terrorist groups but I guess the terrorist group was supposed to be more scary.