Comcast Offers Wi-Fi Motion Alerts Without Extra Hardware—With a Privacy Trade-Off

Comcast is rolling out a home-monitoring feature that can detect movement using Wi-Fi signals rather than cameras or dedicated sensors. Called WiFi Motion, the service is part of the company’s Xfinity Shield suite and is available at no additional charge to eligible Xfinity Internet customers with compatible routers. The system analyzes changes in radio-frequency signals traveling between a router and connected devices on the same network. Disturbances in those signals can indicate movement inside the home. When activity is detected, the Xfinity app can notify the customer and indicate where the motion occurred. Users can reportedly adjust the feature in several ways, including choosing which connected devices trigger alerts, setting active hours, and configuring the system to disregard pets. No hardware beyond the existing compatible router and networked devices is required. That convenience comes with a significant privacy question. According to New Atlas’ account of Comcast’s terms, enabling the feature could give the broadband provider information about when a home is occupied or empty and about residents’ movements. The article says Comcast’s legal language allows the company to sell such data to third parties or provide it to law-enforcement agencies without notifying customers. WiFi-based motion detection is not new. The technology has previously been explored for applications including detecting falls among older adults, and similar home features have been attempted by companies including Philips and Verizon. However, those efforts did not become broadly successful, and it remains uncertain how widely Comcast’s service will be adopted. There are also security concerns beyond Comcast’s own handling of the information. New Atlas cites 2019 research from the University of Chicago and the University of California, Santa Barbara, showing that movements could be inferred from Wi-Fi signals leaking from connected devices. Such detection could potentially be carried out with a smartphone from outside a home. WiFi Motion is not a professionally monitored security system. It sends alerts to the customer but does not provide an operator who watches for intrusions or contacts police. Customers seeking that level of service would need a conventional professionally monitored or do-it-yourself system, generally involving additional equipment and, in some cases, monthly fees.