At first glance, it's one of those things that appears relatively benign: Amazon received federal approval the other day to develop a device for tracking your sleep patterns.
When you look closer, though, questions arise.
Will the device's radar sensors become an even more intrusive threat to our privacy than the microphones and cameras that the likes of Amazon, Apple and Google already have in millions of homes?
And what exactly does it mean having a radar-wave emitter beside your bed? Is it safe?
First the good news. Every expert in radar technology I consulted shrugged off the potential risk of being bathed all night in low-level electromagnetic radiation.
"Even though you might spend a lot of time next to this thing while sleeping, you would get much more harmful exposure by working outdoors for a similar length of time," said Paul Siqueira, a professor of electrical and computer engineering at the University of Massachusetts Amherst.
In terms of radiation output, he told me, "compare this to something like a lightbulb."
Dustin Schroeder, an assistant professor of geophysics at Stanford University who uses radar to study the planet, said the technology Amazon was proposing isn't that different from signals emitted by cellphones and other wireless devices.
"Since I have those things in my room," he said, "I'd feel similarly comfortable, from a safety point of view, with one of these radar systems."
As for privacy, though, that's a different matter.
I made passing reference to Amazon's new technology in a recent column on how the pandemic had resulted in what one expert called "an epidemic of sleep deprivation."
A recent study by the American Academy of Sleep Medicine found that more than half of all Americans have had problems sleeping since COVID-19 arrived.
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.
But because Amazon is the much more aggressive retailer, and because it dominates the market for smart speakers and displays, Amazon's interest in radar-powered devices represents the bigger shot across Americans' privacy bow.
"Surveillance as a service has come to sleeping technology, and it's as creepy as Silicon Valley gets," said Andrew Guthrie Ferguson, a law professor at American University who focuses on privacy issues.
"The privacy of your bedroom is a place that deserves the utmost protection from outside forces, especially from private companies without much regulation or oversight," he told me. "Companies wishing to monetize sleep habits are signaling that there is nowhere outside their reach."
In its request for Federal Communications Commission approval, Amazon acknowledged its radar technology would "operate at higher power levels than currently allowed." It would be "used for sleep tracking and could help improve consumers' awareness and management of sleep hygiene."
The company described its radar sensors as "capturing motion in a three-dimensional space." This suggests that rather than logging all the tosses and turns of a restless night's sleep, as wearables now do, the new device would project an electromagnetic bubble over users.
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," according to the FCC application.
Needless to say, unless you turned it off, it would keep tabs on — and share with Amazon — anything that happens within the bubble, sleep-related or, ahem, otherwise.
"Can sleep-tracking data reveal how many people are in the bed?" wondered Vitaly Shmatikov, a computer science professor at Cornell University.
"Imagine the sleep-tracking data combined with Fitbit data combined with location data from people's cellphones," he told me. "The information gathered by each separate device may appear innocuous, but the accumulation and aggregation of data feeds from multiple trackers can reveal intimate details about users' lives."
Gaia Bernstein, director of the Institute for Privacy Protection at Seton Hall University School of Law, said radar devices that watch you as you sleep were "particularly concerning" because "federal health privacy laws do not regulate companies like Amazon."
"Amazon will get access to sensitive health information about us that it can use freely," she 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.
Although being radar-tracked during sleep is one thing, perhaps the more troubling aspect of all this is the introduction of a new technology into the home that allows Big Tech to follow your every movement.
Theoretically, radar-equipped smart devices would be able to "see" all activity in a room and possibly even help identify those present.
"The technology will be used to observe many people through many devices, most of whom don't have any idea they're being watched," predicted Joshua Fairfield, a law professor at Washington and Lee University who focuses on data privacy.
"Beyond the absolute certainty that this technology will be used to observe people who do not know or consent to being observed," he told me, "it erodes our sense of not being watched. Already our houses are the least private place we live our lives."
Fairfield added: "This kind of innovation is the worst of the internet of things — unnecessary except for advertisers and data capitalists, and with the extra effect of moving surveillance into the center of the most vulnerable spaces and times."
In short, radar sleep trackers probably won't give you cancer or cause any other health problems. But they represent a significant advance in Big Tech's ongoing efforts to spy on you throughout the day (and, apparently, the night).
I posed a simple question about Amazon's latest advance to the experts I contacted: Clever or creepy?
The consensus answer: Both.