Bystander privacy is the risk to people nearby when a device can capture images, audio, location, or other data without their clear knowledge or consent. It is a major issue for wearables, smart glasses, always-on cameras, and voice assistants, because the person operating the device is not the only person affected.
In cyber security, this matters because privacy controls must protect both the user and everyone in the device’s field of capture. Weak indicators, broad data retention, cloud upload by default, or unclear permissions can expose conversations, faces, workplaces, or locations. Defenders reduce this risk with visible recording lights, audible alerts, local processing, short retention windows, and narrow sharing settings. Attackers or careless developers can exploit hidden capture, poor consent design, or unsafe integrations to collect more data than people expect.