This was first published on May 18 by the Forward . Sign up here to get the latest stories from the Forward delivered to you each morning. After a white supremacist allegedly gunned down 10 African-Americans at a Buffalo grocery store Saturday, two of the social media websites he used to plan and promote the attack — Twitch and Discord — announced quick action in response. The 18-year-old suspect identified by police appeared to have used Twitch to livestream a video of the shooting as it took place. The company, which is owned by Amazon, announced that it had removed...