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What your Bluetooth devices reveal

blog.dmcc.io

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Re: What your Bluetooth devices reveal

#81

Post by spockz »

luma wrote: post #78
trashb wrote: post #9

> We’ve normalised the idea that Bluetooth is always on. Phones, laptops, smartwatches, headphones, cars, and even medical devices constantly broadcast their presence. The standard response to privacy concerns is usually “nothing to hide, nothing to fear.” I guess anything you send out can be used to profile you. Some of my friends live on a farm near a semi busy road, however far enough from other farms to not be ab…

You can do this for much cheaper - all four of your tires are broadcasting a unique ID to report tire pressure, the radio to pick it up is cheap (because cars), and TPMS has no facility to randomize or otherwise secure this.

Not all cars have active TPMS. my Volvo xc90 had them but in later models they switched back to passive ones. So it is not even a given for higher end models.

Re: What your Bluetooth devices reveal

#82

Post by Gigachad »

luma wrote: post #78
trashb wrote: post #9

> We’ve normalised the idea that Bluetooth is always on. Phones, laptops, smartwatches, headphones, cars, and even medical devices constantly broadcast their presence. The standard response to privacy concerns is usually “nothing to hide, nothing to fear.” I guess anything you send out can be used to profile you. Some of my friends live on a farm near a semi busy road, however far enough from other farms to not be ab…

You can do this for much cheaper - all four of your tires are broadcasting a unique ID to report tire pressure, the radio to pick it up is cheap (because cars), and TPMS has no facility to randomize or otherwise secure this.

It’s actually even easier, your car has a plate on the front with a unique ID that a camera scans, often to automatically track your park time for ticketing.

I can’t really care about obscure Bluetooth tracking when every business has CCTV doing facial recognition.

Re: What your Bluetooth devices reveal

#83

Post by officeplant »

mcosta wrote: post #74
officeplant wrote: post #51

Earlier quoted context omitted.

With iOS the easiest way to make sure it off and stays off is to build a shortcut to cut off wifi/bluetooth. Otherwise it's typically off until you get geolocated as being back home/work and wifi comes back on. I have a "store mode" button that just kills wifi/bt that I hit before I go into any store.

what do you gain doing this?

Peace of mind that I'm not being tracked around the store by wifi/bt, and/or having my device fingerprinted for further identification on future visits.

Re: What your Bluetooth devices reveal

#85

Post by shafoshaf »

reaperducer wrote: post #76
nofunsir wrote: post #67

Earlier quoted context omitted.

iBeacon. They know what shelf you're standing in front of. What products you touch and read. Ever been in an Apple store? Look up. In the dark voids between the edge-to-edge backlit ceiling. There are secrets there. Watching you.

Macys pioneered it before there even were Apple Stores. Back when most people didn't even know their phones had Bluetooth.

Macy's has Santa clause since 1947 because that is when Miracle on 24th Street came out. And he even knows when you are sleeping.

Re: What your Bluetooth devices reveal

#86

Post by scottlamb »

AlotOfReading wrote: post #71
scottlamb wrote: post #62

Earlier quoted context omitted.

> We had a discussion that it would be easy to determine who was passing by at what times due to these especially when you can "de-anonymize" the data for example link it to a numberplate. You could also read the numberplate directly with OpenALPR. It can be finicky to set up a camera to do this reliably in all conditions (particularly at night and high speed) but once done you could detect any car passing, not just…

There's a difference between public and Public. I go outside with my face visible and I don't mind if my neighbors see me. I do mind if my neighbors stand outside my door with a notepad sketching faces every time they see me or anyone else, especially if they're selling the data. Systematic tracking that isn't subject to the constraints of human memory and apathy fundamentally changes the equation.

> Systematic tracking that isn't subject to the constraints of human memory and apathy fundamentally changes the equation.

I definitely don't approve of mass collection across many cameras, accessible to who-knows-who with minimal if any privacy controls (Flock). But it wouldn't surprise or bother me if my next-door neighbor had ALPR enabled, as long as it's not part of that cloud. YMMV.

Full disclosure: I develop an open source home/hobbyist-oriented NVR, although it doesn't have an ALPR feature or any other analytics today.

Re: What your Bluetooth devices reveal

#88

Post by ssl-3 »

spockz wrote: post #81
luma wrote: post #78

Earlier quoted context omitted.

You can do this for much cheaper - all four of your tires are broadcasting a unique ID to report tire pressure, the radio to pick it up is cheap (because cars), and TPMS has no facility to randomize or otherwise secure this.

Not all cars have active TPMS. my Volvo xc90 had them but in later models they switched back to passive ones. So it is not even a given for higher end models.

That's not quite the end of the road, though: The tires themselves often have RFID tags embedded.

https://rfid.michelin.com/what-is-rfid/

Re: What your Bluetooth devices reveal

#89

Post by bigiain »

kccqzy wrote: post #43
0x1ch wrote: post #19

Earlier quoted context omitted.

I was wardriving my neighborhood and realized my elderly neighbor's CPAP machine is broadcasting some type of BT signal 24/7. I imagine it's transmitting some important stats, but it did make me have a 2nd thought about medical devices being IoT or BT enabled.

> being IoT or BT enabled Please don’t conflate these two. I have lots of BLE wearables and other sensors. They only send data to my own computer which I control, unlike IoT devices which by definition send to a third party on the Internet. To me it is far more important to protect against strangers on the Internet versus someone wardriving the neighborhood. On a related note, did you know that EU has a Radio Equipme…

> I have lots of BLE wearables and other sensors. They only send data to my own computer which I control

That's perhaps technically correct, but a naive interpretation of the risk. I don't need to see the data your BLE devices are sending you, all I need is traffic analysis and meta data from the signals they are broadcasting - and they broadcast that to anyone within detection range which includes attackers with much higher gain antennas than you who can likely pick up those broadcasts at ten times the distance any of your devices will communicate at.

"Flying helicopters low and slow over the Tucson desert in Arizona, the FBI has been using "signal sniffers" to try to locate Nancy Guthrie's pacemaker.

As the search for the 84-year-old mother of US Today show anchor Savannah Guthrie entered its third week, investigators took to the sky with advanced bluetooth technology.

They were hoping to pick up signals emitted from the device implanted in Ms Guthrie's chest to help trace her whereabouts, US media outlets NewsNation and Fox News reported."

https://www.abc.net.au/news/2026-02-16/nancy-guthrie-pacemak...

Re: What your Bluetooth devices reveal

#90

Post by stirfish »

luma wrote: post #78
trashb wrote: post #9

> We’ve normalised the idea that Bluetooth is always on. Phones, laptops, smartwatches, headphones, cars, and even medical devices constantly broadcast their presence. The standard response to privacy concerns is usually “nothing to hide, nothing to fear.” I guess anything you send out can be used to profile you. Some of my friends live on a farm near a semi busy road, however far enough from other farms to not be ab…

You can do this for much cheaper - all four of your tires are broadcasting a unique ID to report tire pressure, the radio to pick it up is cheap (because cars), and TPMS has no facility to randomize or otherwise secure this.

I've had trouble reading these from more than a few feet away, but I concede that I have no idea what I'm doing
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