The internet is not responsible for America's mass shooting epidemic. The single most salient factor is easy access to guns designed for mass killing. But poisonous ideologies such as white supremacy are increasingly incubated online before bursting into the world wielding an assault rifle, and radicalization is easier than ever when propagandists can broadcast their beliefs in an instant to millions, who will broadcast them to millions more.

"The perils of the internet and social media cannot be ignored, and they will not be ignored," President Donald Trump said on Monday. It is ironic to hear Trump demonize platforms for promoting radicalization even as his administration accuses those very same platforms of censorship in response to their efforts to reduce radicalization. But the peril is real, and the question is what paying attention actually looks like.

The massacre in El Paso, Texas, this past weekend began with a racist manifesto, as did the massacres at the Chabad of Poway synagogue and in Christchurch, New Zealand. All of these appeared, minutes before the shooting, on 8chan - a messaging board that operates on lawlessness. Posters celebrated this weekend's alleged perpetrator in El Paso as "our guy"; the goal is to beat the last guy's body count, referred to in a ghoulish gamification of large-scale violence as a "high score."

There are ways to drive 8chan into deeper recesses of the web if not off the web entirely, starting with the services that provide the site technical support turning it away. Two such services have done so this week, forcing 8chan at least temporarily offline. There is a worry that hiding 8chan and similar forums from sight could make threats more difficult to spot, but that risk is outweighed by the advantage of making it more difficult for everyone to spot 8chan. Radicalization is a problem of falling into a rabbit hole. The rabbit hole should be as difficult as possible to stumble into.

Even then, erasing the ecosystem of right-wing terrorism is a monumental task. Larger, more responsible platforms can do their part, stepping up their own efforts against white-supremacist content, adjusting their algorithms so that they do not promote posts that push people toward even more extreme parts of the web, or blockading content that originates in forums infamous for incitement. But their ability to act has limits, as does the scope for government's action. Authorities should dedicate more resources to stopping the next shooter before he has a chance to shoot, yet every effort will involve trudging through a morass of memes and irony designed to disguise threats as jokes and jokes as threats. The greatest power of this machine of racism and mass murder is its inscrutability.

Getting rid of 8chan would not get rid of right-wing terrorism on the internet, and getting rid of right-wing terror on the internet would not get rid of right-wing terrorism in the country. But there are steps we can take today, and there's a commitment we can make for tomorrow: to confront this ugly racism everywhere it lives.

The Washington Post