A recent survey from Elon University’s Imagining the Digital Future Center found that half of Americans now use AI chatbots like ChatGPT, Gemini, Copilot and Claude, and a Stanford Institute for Human-Centered AI study analyzing the privacy policies of six top US AI chat system developers — OpenAI’s ChatGPT, Google’s Gemini, Anthropic’s Claude, Amazon’s Nova, Meta’s MetaAI and Microsoft’s Copilot — found all appear to use customer conversations to “train and improve their models by default,” with some retaining data indefinitely. Cybersecurity expert George Kamide said people underestimate how much shared information can be “stored, analyzed, and potentially reused,” warning that conversations containing personal identifiers, sensitive data or confidential information could become part of a dataset beyond the user’s control. Information security expert George Al-Koura said sharing personally identifiable information — including full name, home address, phone number, and government ID numbers like social security, passport or driver license — risks identity theft, phishing or data brokerage activities. Files uploaded with prompts could also be used for training the model.