“Privacy Concerns Abound With Amazon's Sleep-Tracking Tech”, 16 July 2021.

... Sleep monitoring is a growth industry for Silicon Valley. It's a selling point for wearables such as the Apple Watch and Fitbit. Now such systems are taking root in the home.

In March, Google revealed the latest version of its Nest Hub smart display. It incorporates what the company calls Soli sensors, which are very similar to what Amazon is apparently now planning to put into Alexa-powered gadgets.

[...]

The company described its radar sensors as "capturing motion in a three-dimensional space." ... It would then monitor all movement within that bubble throughout the night "with a higher degree of resolution and location precision than would otherwise be achievable"..

[...]

"Amazon will get access to sensitive health information about us that it can use freely," [Gaia Bernstein, director of the Institute for Privacy Protection at Seton Hall University School of Law] warned.

Sleep data would obviously be highly valuable to a company that runs an online pharmacy and sells pillows and bedding, which, as it happens, Amazon does.

I asked the company for details about how it planned to use the radar technology and what it would do with the data. No one responded.

[...]

Theoretically, radar-equipped smart devices would be able to "see" all activity in a room and possibly even help identify those present.