Thoughtful and sombre commentary by Kevin Roose:

Now, online extremism is just regular extremism on steroids. There is no offline equivalent of the experience of being algorithmically nudged toward a more strident version of your existing beliefs, or having an invisible hand steer you from gaming videos to neo-Nazism. The internet is now the place where the seeds of extremism are planted and watered, where platform incentives guide creators toward the ideological poles, and where people with hateful and violent beliefs can find and feed off one another.

So the pattern continues. People become fluent in the culture of online extremism, they make and consume edgy memes, they cluster and harden. And once in a while, one of them erupts.

In the coming days, we should attempt to find meaning in the lives of the victims of the Christchurch attack, and not glorify the attention-grabbing tactics of the gunman. We should also address the specific horror of anti-Muslim violence.

At the same time, we need to understand and address the poisonous pipeline of extremism that has emerged over the past several years, whose ultimate effects are impossible to quantify but clearly far too big to ignore. It’s not going away, and it’s not particularly getting better. We will feel it for years to come.