Tell HN: Gemini trains on chat history, even for subscribers (personal accounts)

Why it matters

Google has confirmed that chat activity from personal Gemini subscriptions is used to improve its services, including training generative AI models, whenever the Keep Activity setting is enabled. Paid subscribers have no dedicated opt-out; the only ways to avoid this usage are disabling Keep Activity or using temporary chats, and disabling the setting causes saved sessions to be deleted after a set retention window. Google also discloses that a subset of chats are reviewed by humans, and that chats read by reviewers are retained for up to three years even after a user deletes their activity. The company explicitly advises users not to enter confidential information that they would not want a reviewer or Google to see. The story matters because it undercuts a common assumption that paying for a subscription shields users from having their data used for model improvement. The author notes learning this late and credits a Hacker News user for surfacing the policy in another thread.