Users on the anonymous message board site 4chan shared links to a livestream of a mass shooting at a German synagogue nearly 300 times after the shooter reportedly made references to the chans in his video and manifesto, according to a review by Media Matters.

On October 9, a gunman killed two people and wounded two others outside a synagogue in Halle, Germany. The alleged shooter uploaded video of the attack to the livestream platform Twitch, from where it was shared by multiple channels on the Telegram messaging app. White nationalists on Telegram applauded the shooting and video, during which the alleged shooter complained about feminism and declining birth rates and claimed, “The root of all these problems is the Jew.” (One white nationalist channel even urged its followers to target the CEO of the Anti-Defamation League after he condemned the shooting.)

During the livestream, the alleged shooter also called himself “Anon,” seemingly a reference to a term used by the anonymous users of 4chan and 8chan to describe themselves. According to The New York Times, the reported manifesto was written in English “to draw the attention of an audience wider than just other extremists in Germany,” and it also referenced a specific 8chan employee.

A Media Matters search of 4chan found nearly 300 links shared to variations of the livestream, including about a dozen links to a livestream on Twitch and the alleged shooter’s Twitch account, nearly 50 links to the livestream uploaded to video sharing website LiveLeak, more than 170 links to hosting service BitChute, a link to harassment message board site Kiwi Farms, and more than 60 links to an upload of the alleged shooter’s video on a site that describes itself as “the world's leading censorship-free gore site.”