I hope he gets the charge reduced for the murder threats.
No, I'm seriously. I know he had child porn, and he should pay the price for that. But it sounds like his 'threats' were a joke. A sick joke, a bad joke, a joke that can't be easily distinguished from a legitimate threat- except in retrospect. It is still a crime, but degree matters in criminal law. If they find no other evidence that he ever planned to hurt anyone, he probably didn't.
The Random board (/b/) on 4chan brings violent criminals, child pornographers and ordinary folks together like no other site I know. I think hanging out there warps peoples' perceptions about consequences and what is permissible, particularly those who are not well adjusted and think they are safe from prosecution. You go there for funny pictures, but get exposed to things you would otherwise never see without seeking them out.
This is not the first time I have read an article about someone who frequents 4chan doing horrible things on the internet, even when they seem to act normally in other contexts. I am not saying that this man is not responsible for his actions or that the 4chan site is, I just hope someone brings up these potentially harmful effects before he is sentenced.