From a New York Times story by Kellen Browning And Ryan Mac headlined “After Buffalo Shooting Video Spreads, Social Platform Raise Questions”:

In March 2019, before a gunman murdered 51 people at two mosques in Christchurch, New Zealand, he went live on Facebookto broadcast his attack. In October of that year, a man in Germany broadcast his own mass shooting live on Twitch, the Amazon-owned livestreaming site popular with gamers.