
"If it was opt-in, nobody would opt in.". That's Twitch's own justification for training Amazon's AI on your streams by default.
"If it was opt-in, nobody would opt in". That's the actual reasoning Twitch gave for why AI training is on by default rather than something users have to actively choose. Here's what that default actually hands over, and how to shut it off.
Amazon can currently pull your streams, VODs, clips, stream chats, and any images or text on your channel unless you opt out. Per Twitch's own FAQ, this data may be used to train "a model developed by Amazon whose purpose is to generate or synthesize text, audio, images, or video", meaning your face, your voice, and your community's chat logs are all in scope by default.
To turn it off: go to your profile picture, then Settings, then Security and Privacy, scroll down, and toggle off "Training for Generative AI".
Two catches that you should be are of even after you opt out. First, it only protects your own channel, if you're chatting in someone else's stream, their setting controls whether your messages get used, not yours. Second, it only applies going forward. Nobody at Twitch can tell you what's already been collected and used to train models before you ever found the toggle.