I wrote a blog post about the hidden ways your location is being tracked without your knowledge.
It’s Play Services.
GrapheneOS my beloved
in the same way you mention cell towers being able to triangulate a device, you can also be tracked with WiFi APs if you’re connected to or even just searching for a network.
Qualcomm has its “IZat” system where:
- every AP’s BSSID your phone sees is sniffed by a program running continuously in the background, mapped to a latitude/longitude if possible (via GPS or any phone location means) and sent to their servers,
- So that other devices can send a list of AP BSSIDs and signal strengths and get a triangulated location within 5-10 meters.
So the server ends up with a global database of AP locations, and also the location of every device in the world using the service within ~5-10 meters.
They’ve had this in action since 2012.
IZat
Article about -> https://www.theregister.com/on-prem/2023/04/27/are-qualcomm-chips-snooping-on-you-no-not-quite/1100433
Situation seems muddled. Article claims its opt-in, but who knows, I don’t put much trust in claims like that. The idea of a local service to reduce power reqs of a GPS radio seems OK. But this allegedly sends loc data back to Qualcomm, which seems unnecessary. Mfgs like to muddle everything up so features you want, get tied to things you don’t.
Faraday pouches are our friend.
How much of these described techniques can GrapheneOS prevent?
GrapheneOS can prevent IMSI Catchers, App-Level Location Tracking, Wi-Fi MAC Fingerprinting. but you are still vulnerable to other types of tracking methods.
3,4 and 5. 1 and 2 require you to not have cell service, which is possible for any device.
Thanks, really informative article.
You’re welcome.
I have a question about methods 1 & 2: do you know if having your phone in wifi calling mode with airplane mode on, prevents that form of tracking?
No. The wifi you are connected to, still leak your location data.
Even if you’re using a VPN?
Yes.
Can you expand on that? That’s a really interesting conclusion and I’d be interested in hearing how that would work.
Personally I use that setup and am quite disappointed to hear that using wifi calling isn’t the best idea.
May I should just have wifi calling off the entire time, but I would appreciate an explanation so I can plan on how to tailor my phone usage next.
Thanks
I’m planning to write a post on this!
Wi-Fi calling still gives your carrier your IP address and location so they can route the call, so it’s not totally private.
Getting around that usually means running a pretty stripped-down setup (no SIM, full VPN, etc.), which gets pretty inconvenient.
What a dumb title GOS does not track it is just a signal that let’s you use math to calculate where you are on the earths surface.
Yes, GPS itself is not a tracking mechanism. But the apps and services you use in your phone is actively using GPS to track your location data. That’s what i mean.
hence “beyond”… you’re good mate ;)
Interesting read. Thanks.
You’re welcome.
