Your Comcast router doubles as a motion detector now - and a potential police informant

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Comcast has announced a new Xfinity router feature designed to improve home security -- but it may come with privacy caveats.

As first reported by The Verge , a new motion-detection feature has been introduced in Xfinity home routers. An August 18 update to the Xfinity app enables millions of routers to monitor movement in the home.

In a press release , the company said the motion detection feature is part of Xfinity Shield, a new offering designed to "redefine intelligent home protection."

Also: Your router may be vulnerable to Russian hackers, FBI warns: 5 steps to take now

While we expect our home routers to have some form of basic cybersecurity protection, such as through filters, firewalls, and strong Wi-Fi encryption protocol support, Xfinity Shield , now available at no cost to existing customers, includes:

The second feature, motion detection, is the most interesting. Xfinity Gateway routers and compatible connected devices work as in-home motion detectors that "detect changes in the home's radio frequency signal between the Xfinity Gateway and a WiFi-connected device" and will alert users via the Xfinity app when activity is detected.

"It provides an added layer of awareness without recording video, capturing images, or identifying individuals," Comcast noted.

Also: The best Wi-Fi routers: Expert tested and reviewed

This is an opt-in feature and is not enabled by default, so you don't need to tiptoe around your living room to avoid setting off alerts.

There's a second layer to Xfinity Shield, called Shield Select. This gives customers an indoor camera, a door/window sensor, cloud video storage, and 24/7 response services with their home internet bundle.

"We believe the network should do more than connect devices," said Jon Gieselman, chief growth officer, Connectivity & Platforms, Comcast. "It should help protect the people, their personal information, and everything within their homes that depend on our most reliable Wi-Fi every day. That's the vision behind Shield: advancing the role of Wi-Fi to both connect and protect the home."