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The aim of terrorism is terror. It’s an easy tautology to overlook, for it appears to carry no information. But terrorism’s aims are political and social, even when its methods are violent.

When a gunman opened fire in a synagogue in Poway, California, near San Diego, on Saturday, he killed one person and wounded three others. Those figures are low by mass-shooting standards, but the attack has broader implications. Anywhere, everywhere, Jewish worshippers might fear similar violence at their own temples. The same distress descended on Muslims after a deadly attack on three mosques in Christchurch, New Zealand, last month. These attacks infect the innocent with suspicion. With no way to know where or when more random violence could erupt, hearts skip a beat with every doorway darkened.

In both the California and New Zealand attacks, the shooters posted notice, motive, and evidence on the anonymous message board 8chan. In New Zealand, Brenton Tarrant published a manifesto linked on the website, and live-streamed his attack on Facebook, via a link also posted to 8chan’s /pol/ (“politically incorrect”) board. The alleged San Diego shooter had also left his designs on 8chan, in an anti-Semitic screed that cited the Christchurch and Pittsburgh synagogue shootings as motivations.

It’s tempting to call the Poway shooter a copycat. He even used many of the same file-sharing services as Tarrant, and promised to live-stream the attack as the Christchurch shooter had done (the stream doesn’t appear to have worked).

But this is 8chan, where irony and dissimulation rule. Leaving behind a cache of semi-concealed documents that betray an extremist ideology offers days of fodder for journalists, media sleuths, and even other 8chan “anons” to pore over. When my colleague Taylor Lorenz and I each wrote about the Christchurch shooting in the hours following it, we both went to great lengths to distance our reporting from credulity. That’s what the 8channers wanted, after all: to incite an elaborate troll, as Lorenz called it. To incite the media to blindly post and repeat Tarrant’s message.

Even the memes themselves became second order after Saturday’s attack. Like Tarrant, the Poway shooter reportedly invoked the “Subscribe to PewDiePie” catchphrase, a decontextualized reference to the popular YouTuber’s own run-ins with anti-Semitism and white supremacy. PewDiePie, whose real name is Felix Kjellberg, called for an end to the meme the day after the Poway shooting, an act that spawned dozens more media stories memorializing the symbol further. The following day, a plane was spotted over New York City towing a banner that displayed the message.

In the past, would-be terrorists were targeted and recruited based on their susceptibility to the support of and inclusion in a group that hoped only to use them for an end. This phenomenon is typically called “radicalization,” the adoption of an increasingly extreme ideology that can eventually lead to the perpetration of violence. But on 8chan, even radicalization is done with self-awareness; the Poway shooter claims to have been radicalized in 18 months. An ordinary person unfamiliar with the perversity of 8chan would be forgiven for wondering if it even qualifies as radicalization when the radicalized is claiming to have known the whole time that he was being duped. And yet, that very duplicity is at the heart of much of the chatter on 8chan.

This is not the duplicity of dissimulation. These terrorists and those that consort with them are not trying to avoid discovery, or mask intent, or even avoid capture. They bask in the uncertain wink-and-nod of their threats, their comments, or their tributes—“Get the high score,” an anon responded to the San Diego shooter’s post—in the hope of shrouding the very idea of a threat, or a comment, or a tribute in uncertainty.

As 8chan’s activity becomes less talk and more action, some contend that the group will incite even more real-world violence. Unfortunately, that does seem likely. But in the meantime, another consequence arises too: The quantity and frequency of online speech make it difficult, if not impossible, to filter and discern the earnestly dangerous messages from accidents, or jokes, or misconstruals. That’s not just the case on 8chan, where posts are crafted explicitly for their anarchic qualities. It’s also true on Twitter, on Instagram, on Facebook, and everywhere else online. What something “really means” has become less important than all the possible meanings a planet’s worth of potential readers might divine from it.

Sometimes those efforts are taken up with purposeful dark ends. In 2017, the Fusion journalist Emma Roller faced a defamation lawsuit after she was duped by an elaborate troll on 4chan (the slightly less awful cousin of 8chan) into believing that the writer Cassandra Fairbanks and the Pizzagate conspirator Mike Cernovich were throwing white-supremacist hand gestures. (Defamation requires malice, and a judge ultimately threw out the case.)

But now people are becoming more aware of the potential for malevolence in seemingly earnest or even innocuous internet content. Whether it originates from 8chan or from fake news planted by Russian operatives, the takeaway is often the same, no matter what meaning it appears to carry: Everything is potentially suspect—every post, every meme, every link, every quote. The internet has become explosive shrapnel of weaponized Milkshake Ducks, each carrying an unknown payload of hypothetical intolerance that the heat of viral transit might expand into real violence.

And yet, like the innocent worshipper at the mosque or the synagogue, it’s become impossible for the everyperson to ignore the internet, to live their life outside it. Nor should you have to either: That’s just a surrender to the terror that is terrorism’s goal. Its purpose is not to kill, maim, or even distress, but to change conversations and attitudes and, thereby, eventually, common practice and even policy.

People are dying in mosques and synagogues. Their murders are neither incidental nor irrelevant, but they are not the only ends of the internet’s shadowy murk. Mass shooters are only the few who signal the extremes of the blight. Anywhere content flows—which is just to say the whole internet—is infected with lies and inventions meant to make you distrust anything as a possible lie or invention. If that doesn’t scare you, then you’re a fool. But if it does, well, that’s the point.

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