By warning users not to submit sensitive data rather than implementing technical controls to prevent sensitive data processing differently, Google effectively transfers liability to users while retaining broad rights to process whatever is submitted.
Every conversation you have with Google Gemini is stored by Google for up to 18 months by default and may be read by human reviewers for safety and quality purposes, meaning sensitive personal information shared in chats could be accessed by Google employees. Your Gemini conversation data may also be used to train and improve Google's AI models unless you opt out, creating a persistent data footprint that extends well beyond the immediate session. You can turn off Gemini Apps Activity at myactivity.google.com to stop future conversations from being saved, and you can delete past conversations from your Gemini activity history on that same page.