Shooter steeped attack in dark internet culture

SAN FRANCISCO — The suspected New Zealand shooter carefully modeled his attack for an internet age. He live-streamed the massacre, shouted out a popular meme slogan and published a long, rambling manifesto replete with inside jokes geared for those steeped in underground internet culture. The gunman, who carried out an attack on at least one of two mosques targeted Friday in Christchurch, posted the manifesto online using the name Brenton Tarrant. It makes him the latest alleged killer to commit mass slaughter alongside a targeted appeal to online communities that breed extremism. Prior to killing six people in Isla Vista, California, in 2014, Elliott Rodger posted an online video and circulated a lengthy document full of grievances. He was later found to have ties to a misogynistic online group known as “incels,” or “involuntary celibates,” who sometimes call for violence against women. Last year, Robert Bowers, the man charged with killing 11 people at a Pittsburgh synagogue, posted threats on Gab, a social media site popular with white supremacists. People who want to discuss such ideas are bound to find each other, said Daniel Byman, a senior fellow at the Brookings Institute. People do things online that they might be hesitant to do in real life, Byman said. That can range from harmless acts, such as emailing someone you would be too intimidated to approach at a party, to sharing, building on and encouraging extremist views and violence. “It enables you to be bolder,” Byman said.