So what's special about Anders Behring Breivik's posts? He does seem particularly obsessed with the problems of Islam and multiculturalism, which he labels 'cultural marxism' and claims, rather weirdly, is an ideology of hate. His world view seems exceptionally simplistic and divorced from reality (from New Years Eve 2009, all translations are my own):
Two basic concepts are emerging as the only ones many use to describe cultural positions:
Cultural conservative (from the word conserve/patriot/nationalist/monocultural) and cultural Marxist (internationalist/multiculturalist/cosmopolitan/globalist).
Even most humanists but also many market liberals are anti-nationalists and therefore by definition cultural Marxists. One supports either multi-culture (cultural Marxist) or monoculture (nationalist), there is nothing in between even though most people dare not admit this yet. Well, there is always multi-culture without Islam which is in between.
At any rate, it's possible that THE [Thomas Hylland Eriksen, a professor of anthropology] does not fill the criteria for a Marxist/communist, but all internationalists are cultural Marxists.
Old definitions often become invalid. E.g. the British Tories who still dare call themselves conservative support cultural Marxism/multi-culturalism and should therefore change their name.
I'm sure you can see where he's going with this: not exactly the voice of reason. He's bats, but batshit stupid rather than simply crazy. His words are part muck-racking (his Marxist label is obviously void of real meaning), part paranoid construction of two fronts in a conflict. His admission that multi-culture without Islam is 'in between' monoculture and multi-culture may suggest that his own nationalism is not so far from his own views on Islam: his Islam being, of course, monocultural in essence. Like so many straw men, his enemy is a model of himself.
In other comments, his conflating of multi-culture and Marxism serve a more explicit purpose. He argues against the notion of 'moderate Islam' by invoking Godwin: there were moderate Nazis as well, Nazis that didn't support the Holocaust. Should we allow moderate Nazism as well? No, he says (2010-02-17):
To me, it seems very hypocritical to treat Muslims, Nazis and Marxists differently. They're all adherents to ideologies of hate. Not all Muslims, Nazis and Marxists are conservative [Freudian slip: he should say radical], most are moderate. But does it matter? A moderate Nazi can, after being defrauded, choose to become conservative [slip again]. A moderate Muslim can, after being denied entrance to a club, become conservative [slip again!] etc.
It's obvious that moderate adherents to ideologies of hate sooner or later can choose conservatism [he's consistent].
Islam(ism) has historically lead to 300 million deaths
Communism has historically lead to 100 million deaths
Nazism has historically lead to 6-20 million deaths
ALL ideologies of hate should be treated equally.
Not a Nazi then: historically, Nazim is 2 to 6% as bad as Islam (in less than 1% of the time, a pedant might add). And in vocal opposition to ideologies of hate. Some guy.
In the end, he posted a partially disguised work application, suggesting the site hires him as an editor for a dead tree publication. From my understanding of the comment, the site was about to hire a paid journalist, an idea ABB criticises as a waste of money since so many fine writers would be happy to work for free (his own writing being atrocious, he had little chance of becoming a paid journalist himself). The tone seems very happy and optimistic, if a little forced. Of course, he wasn't hired. That's his last comment, from 2010-10-29.
All in all, he seems to be borderline retarded and very hateful, ironically on some kind of crusade against his 'ideologies of hate' Islam and 'cultural Marxism'. There's little in his writing to suggest he should turn violent, though.