Comcast is rolling out a software feature that turns some Xfinity home routers into motion sensors. According to The Verge, a new Xfinity Internet app update arriving August 18 enables Wi-Fi Motion on compatible Xfinity gateways at no extra cost, bringing the capability to millions of routers already installed in customers’ homes. TechCrunch also reports that the feature has been added to Comcast’s newer home routers. The system does not require a separate motion sensor. Instead, Wi-Fi Motion watches for interruptions in the home wireless network and uses those signal changes as a proxy for movement, then sends alerts through the Xfinity app. The feature is limited to advanced Xfinity gateways, identified by both outlets as XB7 and newer models. It is opt-in, meaning customers have to enable it in the Xfinity app, and The Verge reports that it can be turned on or off there. Comcast is not positioning the feature as a full replacement for a traditional alarm system, cameras, or dedicated physical sensors, but as a basic home activity-monitoring layer. The Verge reports that Wi-Fi Motion is part of a broader Xfinity Shield service. That free service includes the motion feature, online threat protection for devices against risks such as malware and phishing, and improved parental controls. Comcast is also adding app modes for different use cases, including Home Watch, Away Watch, and Dark Watch, which The Verge describes as a night or sleep mode. The underlying technology is not new, but the consumer deployments have been uneven. The Verge notes that Linksys launched a similar service in 2021 and later discontinued it, while Wiz and Philips Hue have used related sensing approaches in lighting products, with Hue using Zigbee rather than Wi-Fi. Comcast told The Verge it has spent three years refining its algorithms and reducing irregularities in earlier Wi-Fi sensing implementations. The privacy issue is the sharper edge of the rollout. TechCrunch reports that Comcast’s support language says information generated by Wi-Fi Motion may be shared with third parties without further notice in connection with law-enforcement investigations or proceedings, disputes involving Comcast, or court orders and subpoenas. That does not mean every motion alert is automatically shared, but it does mean enabling the feature creates a new category of home-activity data subject to Comcast’s stated disclosure terms. For customers, the trade is straightforward: a free, no-new-hardware home monitoring feature in exchange for allowing the broadband provider to infer activity from the wireless environment. The feature may appeal to users who want a lightweight alert when a home should be empty, but the data path matters because the sensor is the network itself, not a standalone device installed for a narrow purpose. Comcast is also keeping paid home-security hardware in the mix. The Verge reports that Xfinity Shield Select costs $15 per month and includes an indoor camera, a door/window sensor, cloud video storage, and a 24/7 urgent response service. That positions Wi-Fi Motion as the baseline layer, with cameras and sensors still available for customers who want more conventional monitoring. Who benefits: Xfinity customers with XB7 or newer gateways get a no-extra-cost way to receive basic motion alerts. Comcast benefits if the feature increases engagement with the Xfinity app and its broader Xfinity Shield services. Who's exposed: Privacy-sensitive households are the exposed group, because enabling the feature creates motion-derived data about activity inside the home. Users relying on it for security should also note that Comcast is not presenting it as a full replacement for cameras, door/window sensors, or traditional alarm systems.