Your TV can see through walls (2025) (maurycyz.com)

222 points by Curiositry 10 hours ago

numlock86 8 hours ago

Wait for people to learn about that you can listen in virtually anywhere through fiber-optic cables, as sound waves are enough to redirect the light in the cable to a measurable degree by "bending" the cable itself. Special devices to filter these variances out and transform them back to audio signals are a thing. It's only per line though, as any repeating device will just output a new cleaned up signal again.

Oh well, there have always been ways to snoop on someone like that. Back in the day it was CRTs emitting measurable waves through the neighborhood, with some papers even going as far as restoring the displayed image through a wall. Nowadays it's fiber and WiFi, and those seem to be much easier to work with even. Plus everyone carries a device that is tracked by their mobile provider's cell network. shrug

p_l 31 minutes ago

Funnily enough, first time I've seen it mentioned was in Ghost in the Shell manga from 1990s, where Major's side business illegally offers military grade optronic touch/etc senses in artificial skin for cyborgs, using measurements of bending fiber optic loops

neuronexmachina 23 minutes ago

> Back in the day it was CRTs emitting measurable waves through the neighborhood, with some papers even going as far as restoring the displayed image through a wall.

It's been some time since I've thought about Van Eck phreaking: https://en.wikipedia.org/wiki/Van_Eck_phreaking

ClikeX 6 hours ago

You can also listen for audio simply by measuring any vibrating surface with a laser. Which goes all the way back to the late 40s, used by the USSR. |

Fun fact, it was invented by Leon Theremin. The inventor of the Theremin.

dghughes 2 hours ago

1940s? The LASER device was invented in 1960. The Soviet spies used an infrared light beam.

ClikeX 28 minutes ago

fortran77 an hour ago

You are completely wrong.

Here's what Theremin invented: https://en.wikipedia.org/wiki/The_Thing_(listening_device)

ClikeX 29 minutes ago

fouc 2 hours ago

>The theremin is an electronic musical instrument controlled without physical contact by the performer.

ForHackernews 6 hours ago

https://en.wikipedia.org/wiki/The_Thing_(listening_device) is a fun read for people who haven't seen it before

undefined 3 hours ago

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iamnothere 2 hours ago

I don’t get your point. Yes, there’s a lot of eavesdropping techniques available to actors with nation state capabilities (or with a lot of time, money, and expertise). This is another one of them. It’s good to be aware of things like this because it helps you better understand threat modeling for applications that require serious hardening.

There may also be unusual applications of this, like the traffic counting mentioned by another commenter.

(For anyone who needs hardening against things like this, you need a SCIF.)

kurthr 7 hours ago

Just toss a doppler laser interferometer on a window, mirror, etc. At least with fiber-optics you need physical access. Single mode (I think that's most of FTTH) is pretty insensitive to vibration and hard to localize so you'd really have to install something.

taneq 4 hours ago

In this context, is line of sight with the ability to emit and receive laser radiation at the target not ‘physical access’?

andai 6 hours ago

Ah, but of course. How could I forget about my trusty pocket doppler laser interferometer!

ben_w 6 hours ago

JdeBP 6 hours ago

aa-jv 5 hours ago

taneq 4 hours ago

euroderf 6 hours ago

So when AI takes over the world, it will have a convenient tap into every living space of every hoomin. Lovely.

w4der 6 hours ago

Fiber optic interrogators are (for now) expensive and bulky, so I don't think commercial modems are capable of that (yet).

ck2 2 hours ago

trackers are also now becoming near microscopic

they track BUTTERFLIES from Canada to Mexico by attaching tiny trackers with eyelash glue

* https://celltracktech.com/products/ctt-blumorpho

smaller than a tic-tac candy (about two match-heads)

* https://cellular-tracking-technologies.github.io/ctt_documen...

armcat 7 hours ago

Several years back we actually made use of the principle mentioned in this post, to more systematically count traffic on the roads [1]. In our case we used LTE/4G radio, and we could even estimate the direction of travel, as well as the type of traffic (pedestrian, small vehicles, large vehicles). It was more accurate than Google Maps because it was independent of the moving phone, i.e. it was "sensing the obstacles in the environment".

[1] "Traffic Flow Estimation using LTE Radio Frequency Counters and Machine Learning", https://arxiv.org/abs/2101.09143

swerner 8 hours ago

As anyone observed who had a TV with just basic analog terrestrial antennas, before cable and satellite dishes - it does make a difference to the signal, when and where you stand and countless pieces of physical comedy in TV shows incorporated that.

reddalo 6 hours ago

As soon as I've read your comment, I've thought about this Mr. Bean's sketch: https://www.youtube.com/watch?v=4S9-vDow2d0

pmontra 6 hours ago

And reflections on other buildings (which usually cannot be compensated for,) wind bending antennas, etc.

taneq 4 hours ago

Ah, the old ‘stand in a funny pose so the family can watch the show’. Such a classic. :P

1e1a 8 hours ago

See these for a very low cost (<$10) method for observing WiFi and some LTE spectra:

https://news.ycombinator.com/item?id=49922674

https://espargos.net/espsdr/

doginasuit an hour ago

I thought this article was going to be about putting a webcam on the other side of the wall and streaming through the TV, which somehow had never occurred to me and I want to try it now.

fzeindl 9 hours ago

Amazing book about similar topics: “Silence on the wire” by Michal Zalewski

https://www.amazon.de/Silence-Wire-Passive-Reconnaissance-In...

6c696e7578 5 hours ago

Anything in my price range?

fzeindl 4 hours ago

What is your price range? You could check your local library for borrowing it.

nubinetwork 2 hours ago

I know this is written to sound scary, but it's been like this since the invention of the radio/telegraph (late 1800s?). You're getting blasted by rf almost continuously, unless you live in a bunker.

Reubachi 2 hours ago

This is written to sound scary/capatalize on a relatively underdiscussed snooping mechanism.

But it isn't at all like straight UHF/VHF radio intereference spectra analysis or whatever we want to call it.

Wifi, Cell network bands, bluetooth and hard fiber lines are all far more exploitable than "regular" RF . A police squad car equipped with the RF package (which convienetly comes from defense contractors) can grid out your home and hotspot people, devices, etc. This is only possible due to exploits/abusing these standards and cooperation w/ device/tech vendors.

Is this a problem? Eh, not for me where I live. Is it illegal? I am not versed enough to know how procedural/ y the books this is. But it is odd that a passing police vehicle potentially has unmarshalled/warrentless seach running 24/7.

nubinetwork an hour ago

In order for that to work, they would have to stand on one side of your house, and scan from the other side. If they're already surrounding your house, they might as well just bust in.

fwip 12 minutes ago

NooneAtAll5 an hour ago

"I know this sounds scary, but don't worry - all this spying won't give you cancer!"

reactordev 3 hours ago

I threw away all TVs in my house after the proliferation of ads on the Home Screen. Sorry, the only value a TV has is displaying images and audio at large sizes. Not getting me to shop. So I decided to get rid of them all and now I use large monitors and projectors. Make TVs dumb again.

iamnothere an hour ago

The article is about radio waves from TV broadcast towers, not the TV in your home.

VCFundedGenYer 3 hours ago

This makes no sense.

This problem is solved via two ways (or both at once):

- Pihole

- Unplug the TV from ethernet and disable wifi

All my TVs display no ads because they are jailed.

rapnie 2 hours ago

> Unplug the TV from ethernet and disable wifi

This likely requires opening the case and physically disabling (hence knowing what you are doing). Or the TV will find other devices to transmit the data. Not an easy measure for everyone.

bethekidyouwant an hour ago

undefined 2 hours ago

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rapnie 2 hours ago

Tangential. Of both LG [0] and Samsung [1] smart TV's it is known they spy on you any way they can. Does someone know if they do that too for models sold in Europe, which would likely be in violent breach of GDPR?

[0] https://www.youtube.com/watch?v=6IFVTcM28KA (Gamers Nexus findings)

[1] https://www.youtube.com/watch?v=VFx1DyAjxYc (LMGClips summary)

undefined 8 hours ago

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darkwater 8 hours ago

Now, about the wifi part, why isn't there an Home Assistant extension that detects already room presence magically exploiting all of this??

sudorm-rf--no-p 8 hours ago

timthorn 8 hours ago

darkwater 6 hours ago

But this relies on Hue. I would like something at HA level directly, aka a zero-effort solution if you already run a zigbee swarm either directly controlled by HA or via zigbee2mqtt

gbxyz 9 hours ago

mrmlz 7 hours ago

As made popular in Cryptonomicon!

walrus01 8 hours ago

see also, presence detection of humans via wifi signals: https://arxiv.org/html/2308.06773v2

trafalgar_nah 35 minutes ago

Had to pull out my calculator to digest the calculations, phew. I'm a math major that's been out of the game for a bit, I guess i'm getting rusty.

ThePumpkinGod 9 hours ago

So, a bad actor can now know when I'm at my house or not, I'm sure that's fine and won't be problematic

ClikeX 6 hours ago

Bad actors, and any WiFi capable hardware in your house. There's an official spec for it[1], and some routers already have the option built in. I remember seeing papers about this over 10 years ago, someone at MIT did it for a paper.

Philips Hue also has it built in to their newer lights, where they measure the Zigbee signals. They call it MotionAware[2]. Basically anything with an antenna and a bit of compute is able to do this now.

[1] IEEE 802.11bf-2025 [2] https://www.philips-hue.com/en-hk/support/article/motionawar...

jaapz 5 hours ago

Even philips hue documentation is now vibed

ClikeX 3 hours ago

reaperducer 5 hours ago

There's an official spec for it[1], and some routers already have the option built in.

~~Comcast~~ Xfinity actually advertises it on the radio as a feature.

st_goliath 6 hours ago

> So, a bad actor can now know when I'm at my house or not.

A bad actor who wants to act on that information can just wait near your house on a workday morning and watch you leave, likely not to return for the better part of the day. No techno-voodoo required.

nkrisc 3 hours ago

Bad actors have been doing that for millennia using their eyes.

This makes it more remote and subtle, but it’s not a new threat.

pluralmonad 19 minutes ago

Not just remote, automatic as well. IMO an entirely new class of threat over "my neighbor knows when I'm home."

rightnutwingjob 9 hours ago

Even having three security cameras around the perimeter of your house can allow quite precise location and activity detection inside the house via their audio steams.

Those mics can be quite sensitive.

ThePumpkinGod 9 hours ago

I don't have security cameras in my house but that's actually interesting to see how things most people have in their house can (and does?) used to spy on them.

pmontra 6 hours ago

motbus3 7 hours ago

Yes. But depending who is doing the work they can just see what Bluetooth devices are around each hour of the day too... It sucks that everything we have seems to be usable against us

jack_pp 3 hours ago

SlightlyLeftPad 7 hours ago

Really? They can’t seem to pick up a conversation happening directly in front of them.

alt227 6 hours ago

Or they could just knock on your door and see if you answer.

cowlevel 9 hours ago

They already knew this from your cell phone not being in airplane mode.

ThePumpkinGod 9 hours ago

If I ever try to hide (which is probably impossible at this time and age), I will probably just break my phone not like I can use it anyways every single act in it sends data to too many places to count.

guax 7 hours ago

lencastre 9 hours ago

there is always the risk of the isolated Faraday caged house

gruez 7 hours ago

Can't they already do that by snooping on ARP traffic on your home LAN? Failing that, if they can get whatever shitty wifi chipset they're using to enter promiscuous mode, they can also sniff all STAs that are in the vicinity, and with some ML they can probably figure out which MAC belongs to your phone.

fortran77 an hour ago

There's no TV here. There's an ATSC broadcast signal and an SDR with a waterfall display.

crunkmcgoop an hour ago

I’d rather have the Chinese lady with the nice ass sex my secrets out of me

thopterek 9 hours ago

Thank you for more paranoia

sweetdingoes 5 hours ago

Awareness of possibilities is not paranoia. One implies sickness. Healthism?

rightnutwingjob 9 hours ago

π RuView turns commodity WiFi signals into real-time spatial intelligence, vital sign monitoring, and presence detection — all without a single pixel of video.

https://github.com/ruvnet/RuView

inexcf 7 hours ago

Just so anyone who reads this knows: This is a well known SCAM repo. The install instructions are incomplete and when you manage to get it running you will realize the data it produces is just random except for pre-recorded simulated data. If you check youtube for it you will find hundreds of completely AI generated Videos with not one of them showing the actual thing working. And all while trying to sell you some hardware.

https://github.com/deletexiumu/wifi-densepose " SCAM ALERT: Technical audit reveals this project is a non-functional AI-generated facade with fake CSI data, no trained models, and suspected star inflation"

NoboruWataya 3 hours ago

IAmBroom 24 minutes ago

neverbeenasked 7 hours ago

yeah, now I gotta unplug TV too

iamnothere 2 hours ago

That won’t help, this is about TV station signals broadcast from outside your house

protocolture 5 hours ago

Thats nothing, my old tv could predict incoming phone calls.

alt227 5 hours ago

When I was young I could tell when the neighbours turned on their tv by the UHF whine.

blurbleblurble 2 hours ago

IEEE ISAC, look it up

undefined 21 minutes ago

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codingboyamit 4 hours ago

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finn888 4 hours ago

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jasperrhodes 8 hours ago

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pbodyvstheworld 6 hours ago

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