[pron]

I don't blame 4chan at all, and neither does the author (who, BTW, doesn't talk about "4chan" but about one specific board). Hilarious that you read it this way. But when writing a piece of cultural criticism, it's important to categorize social groups based on cultural narratives (or currents), and the narratives on that 4chan board overlap with those found in the murderers' manifestos and intimidation campaigns. That within every narrative-group some people take things much, much further than others goes without saying. It also goes without saying that discussion groups -- online or off -- are better indicators of the "mainstream" of the groups they represent rather than the most extreme (people who end up behaving violently often eschew gatherings), and most certainly cannot be blamed for violent action. Nevertheless, all sorts of ideological violence are associated with some non-violent ideological groups in some way, and it is disingenuous to claim that there is no cultural association whatsoever between those anti-women rampages and certain online communities.