Re: Cell phone tracking

On Wed, 16 Jul 2025 11:37:32 +0200, Carlos E.R. wrote :

On 2025-07-16 05:54, Marion wrote:

On Wed, 16 Jul 2025 02:09:07 +0200, Carlos E.R. wrote :
 

On 2025-07-15 21:47, D wrote:

On Tue, 15 Jul 2025 17:04:48 +0000, Anonymous <nobody@yamn.paranoici.org> wrote:

Message-Id: <20250715.170448.c5f8b4a9@yamn.paranoici.org>
>
I just heard an engineer describing how phones are doing something new
now in tracking people.  Some phones today (probably android and apple)
are continuing to track you after you turn the phone off and store the
data on your phone.  When you turn them back on, the phone then sends
the tracking data to a server.  The only way to defeat this is to put
your phone into a faraday bag, most that don't work.

>
This is ridiculous.

 
I care about privacy, but I don't understand "tags" nor "findmyphone"
tracking yet, mainly because I haven't ever thought about using them.
 
However, what little I do know is that the iPhone 11 and later, excluding
some SE models have a feature that allows them to be located even when
turned off or when the battery has run out. This is because they have an
Ultra Wideband chip and a "power reserve" feature for the Find My network.
 
This means that even if you turn off your iPhone 11 or newer, it can still
act as a relay for an AirTag's location, and its own location can be seen
in the Find My app. Wikipedia says it's five hours after the battery dies.
  <https://en.wikipedia.org/wiki/Find_My>

 
Read carefully the paragraph I quoted and you will see that the method
of Airtags is not what is described. The paragraph implies that the
phone on its own finds its own location (GPS?), stores it, and then
uplodads it when finally powered up. All that requires significant power.
 
Airtags use low power Bluetooth to request passersby to do the job of
locating them and uploading that location to some central store. Thus
they work for a year or two on a button battery. Possibly could work on
the reserve power of a phone main battery.
 
It is not unthinkable for phones to have Airtag capability, but surely
this must be documented, in order to be useful to the owner, who wants
to find his own phone. To do that, he has to register the Airtag info
somewhere and save that data somewhere else. And possibly the feature
can be disabled or be optional.
 
All this means that the quoted paragraph is ridiculous.
 

 
Android phones have their own "Find My Device" network for locating lost
Android devices but as far as know, they won't work if the phone is off.
 
All this can be wrong, but there is "some" truth to the fact that an iPhone
that "appears" to have a dead battery, can still participate in finding it.

I'm OK with your assessment based on the facts. I was just letting folks
know, in case they didn't know, that some phones aren't really off when
they look like they're off (for tracking purposes like for "Find My").

I never really thought about it before so I don't know more than that.
I never cared enough to look up how Find My or tracking tags work.

I'm reading every post in this thread though, so that I learn from others.