What should I never paste or type into ChatGPT, Gemini or any other AI chatbot?

Leave out anything that would hurt if a stranger read it: passwords, OTPs and PINs, bank and card numbers, Aadhaar and PAN, a medical report with your name on it, other people's private messages or photos, and your employer's confidential files. On personal plans your chats can be kept, seen by human reviewers and used for training. Google says plainly not to enter anything you would not want a reviewer to see, and Microsoft says the same for Copilot. Leaks happen too: in 2025 DeepSeek left over a million lines of logs, including chat history, open on the internet, and ChatGPT and Meta AI users made private chats public by tapping Share. For help with a document, delete names and numbers first, or describe the problem instead.