Google Chrome silently installs 4GB Gemini Nano AI model without user consent

Google Chrome has been found to silently download and install a 4GB AI model file (Gemini Nano) onto users' devices without their knowledge or consent. The file, named weights.bin, resides in the OptGuideOnDeviceModel directory within the Chrome user profile. The download occurs automatically when Chrome's AI features are active, which are enabled by default in recent versions. Users who delete the file find it re-downloaded by Chrome. The behavior was verified on macOS using kernel filesystem event logs, showing the model was installed on a freshly created profile that received no human input. The total install time was 14 minutes and 28 seconds. The author estimates the environmental cost of this push across hundreds of millions of devices at between 6,000 and 60,000 tonnes of CO2-equivalent emissions, depending on deployment scale. The article argues this violates the ePrivacy Directive, GDPR, and computer misuse laws, and criticizes Google for not providing an opt-in, not documenting the behavior, and for the AI Mode pill in Chrome 147 being cloud-backed rather than using the on-device model, misleading users about where their data is processed.