A man who attacked a synagogue in Poway, California, in April, also spent time on 8chan. In his racist manifesto, he used coded white nationalist language found on both platforms. The shooter in the March massacre in Christchurch, New Zealand, had spent time on 8chan, one of 4chan's even more vitriolic offshoots. Perpetrators of recent far-right terrorist attacks have been connected to similar forums. But anonymous online forums like 4chan - a comment board designed to facilitate discussions between users posting threads of text, images, and memes - have remained a toxic, anonymous mixture of hate, bigotry, and misogyny, and have given violent extremists a kind of digital safe space. After a wave of recent attacks by white nationalists across the world, social media platforms have begun cracking down on hate speech.