Yet another privacy nightmare begins: Routers sensing our physical motion through our houses

It would be nice though to be able to case a thousand local joints simultaneously, from the comfort of your living room. Then plan your night’s robbing …

Yup, it definitely has made me a much more productive burglar.

This technology thing? It’s the future, I tell ya!


Also known as the travelling burglar problem.


Some new info: If it can be hacked, it can be made into a standard, I guess. And in this case:

802.11bf started its work in October 2020. It’s devoted to Wi-Fi Sense, where analysis of existing signals at a location reveals a radar-like picture of where physical objects are and how they’re moving. Potential resolution depends on the bandwidth of signal being picked up, with a common-today 100MHz signal able to sense things down to around a metre, and a five-years’-time 10GHz wide signal getting a spatial resolution of about a centimetre. The applications the working group envisage are security, asset tracking, telemedicine for the elderly, gesture control, gaming, and so on, with the higher resolution modes being able to spot things like your rate of respiration, finger position, and body type, potentially around corners or through walls – the same antenna physics that make EHF a condenser for real-life long-distance links means the old assumption that it’ll be effectively shielded by walls no longer holds.
( which has other tidbits as well)

Surely the security implications have been thought of. Surely?


I wonder if your radar signature is greater when wearing a tin foil hat?

Now that hat has to start ejecting chaff periodically.

Maybe they figure that by the time this is deployed and effective, there will be so many cameras in people’s houses that radio frequency imaging won’t make things much worse. :frowning:

I think you might be an optimist. Ironically, we wouldn’t know…

There was a bit about using nanomaterials or some such to enhance radioreflection of walls to do stuff but I quess radio signal (or specific frequncy) blocking paint might become a sought after product.

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For sale: copper mesh* faraday’s cage. Blocks all 2.4G, 5G, 7G and whatever else with wavelenght of 50 Mils or longer. Dimensions: 5 x 30 x 30 inches. Hangs on the wall. Small openings at the bottom allow power and ethernet cables to go through while still effectively blocking the radio waves in the air. Put that blackbox thingy from ISP inside the cage, and rest in peace… errr… assured that no more movement spying is taking place!

*copper mesh: cheap, easy to buy, and much more durable than tinfoil!


I was actually thinking this myself just keeping the router contained in a faraday cage with a tiny hole for the cable and power cord.

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There is a youtube video on that somewhere, they used a couple different cage configurations I think.


The problem, unfortunately, is that the technique allows using signals from other devices and measurements can be done through walls of a house or an apartment complex. Your cage needs to be bigger… a lot bigger :cowboy_hat_face:

I’m not advocating this but foil may be simpler. Although, I wonder, if it would be enough to put the person in the cage… or wrap fully :wink:

There’s a simple rule that I think cuts through the questioning and that’s the Principle of Least Privilege. Does a device need to know this information to do its job? No. Networking is a taxi-cab geometry. A dumb router does one job and that’s the one, for my part, that matters.

Clearly they have ideas around competing with Nest (or integrating with) in terms of smart-home capabilities. For those individuals that are willing to have this data capitalized at some point (is a software service, so I am willing to wager there’s clauses about personal data and potential for resale but in an oblique way), they will buy this. For the rest of us, perhaps we stick with our simple devices that do their singular job well.


The corollary to that is: Privacy and security cost money. The cheapest solution is the all-in-one box that routes and WAPs and switches and spies.

The 802.11bf is just the standard (same series as wifi) so it might be that Nest too will offer devices to have it. Like has been said before, the technique does have beneficial uses as well. @Dwaff cage idea does have a use, to make sure the scenario that @irvinewade points out can be contained - the integrated all-in-one box that someone could use illegally (or at least against wishes) to gather info (which seems from the standard description to be very accurate - possibly even down to keyboard reading like passwords or content as well as biometric info).
From risk management perspective, the separate case is, that it may not be enough to do something about your own device, if your technically challenged neighbor(s) has one too, which may be what they wanted but still leaks info.
And the third scenario is that someone intentionally brings one along to do some “drive-by” scanning from a walkway or road outside. Or, to take the idea to extreme, how about a truck that just drives around the street peeping into peoples homes, recording everything, in the name of public safety…? I might be ok, if something like that could be used only in an emergency, but usually there are marketing applications and misuse and no inbuilt control mechanisms (not sure if there even could be).

On the first, we have the faraday cage option and other means to control or disable the device. Possibly the need for some good old open hardware, possibly from this company. On the second, I can only think about the paint (or wall foil) an possibly some legislative restrictions. On the third… No idea. Maybe everyone (who can afford it) has to have a privacy wall insulation built but that’s got to cause havoc on all the other wireless devices - no more mobile.

An yet, even still, part of me want’s to see this only to get to try what it would be like to have goggles with augmentation that allows to see through walls.


Let’s put it this way … I have an all-in-one router but I have WLAN disabled and the screw-in antennae unscrewed. Hopefully that is enough to slow any kind of wireless sensing down.

The mitigation is to live in a location where this is not practical i.e. too far from neighbours, too far from road. I don’t know what the range would be on this WiFi sensing technology.

I would wonder what the effect of existing deployed construction techniques would be. Specifically:

  • steel-framed house
  • sarking that is used for (external) wall insulation (as distinct from bulk, typically glass fibre, insulation) - maybe that’s “wall foil” (as apparently this use of the word sarking is uniquely Australian)

Consider this: Yeah.... About that anonymized data of yours

Unsure of the relevance but being discussed here: Yeah.... About that anonymized data of yours

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I understand the question around relevance. And I will modify the link to the conversation. The relevance is one’s one home snitching hypothetically.

And if speed is not important, you can use an old hub with 10 base 2 coax. It won’t emanate.

This technology has been around for decades! :stuck_out_tongue_winking_eye: