Pittsburgh Synagogue Shooting Puts Spotlight on Fringe Platforms and Their Partners

As mainstream social-media companies such as Facebook, Twitter, and Reddit try to push racist commentary and hate speech off their platforms, those conversations are finding homes in other corners of the web. They are happening on Discord, a chat service for videogamers, and message boards such as 4chan. Gab was founded explicitly to be a haven for free commentary, no holds barred. Discord says its rules prohibit harassment, threatening messages and calls to violence, and it has shut down accounts over those issues. Grappling with such web speech is proving challenging. It is thrusting an array of companies—from web hosts to payment processors—into the position of being arbiters of free speech. And it has left law-enforcement officials struggling to keep track of hate-filled conversations in remote parts of the web as they search for early tipoffs to tragedy.