[liberationtech] If we want to be anonymous in #azerbaijan we take batteries out of our cellphones

Jacob Appelbaum jacob at appelbaum.net
Mon Jun 18 16:27:39 PDT 2012


On 06/18/2012 07:40 PM, Eleanor Saitta wrote:
> On 2012.06.18 13.29, Parker Higgins wrote:
>> On 6/18/12 8:36 AM, Yosem Companys wrote:
>>> Hi Liberationtech folks, is this always the case? I've heard cases
>>> where people can still be tracked whether they have batteries in
>>> their cell phones or not...
>>
>> I've spoken with mobile security researchers who have given me the
>> impression that this theory hasn't been tested very much. It's
>> theoretically possible that some phones could be recording or
>> transmitting without the main battery, but the equipment that would be
>> required to test is prohibitively expensive and you'd have a hard time
>> demonstrating anything but an evidence of absence.
> 
> Unless there's a specific secondary battery powering a transmitter, it
> is improbable in the extreme that an unpowered passive device can have
> its location tracked at a distance of more than, say, a hundred meters,
> and any tracking at all is extremely unlikely.  Cellphones don't work
> that way, and physics says no, basically.
> 
> Now, *people* are very easy to tail, when you have a human doing the
> work.  That's a different story.  There are almost certainly many more
> pressing issues to worry about when it comes to locational privacy than
> a battery-less phone.
> 

I'd like to remind everyone about the Great Seal bug:
https://en.wikipedia.org/wiki/Thing_(listening_device)

Sometimes the source of power isn't in the device itself.

It might be cheaper to tail someone but in some cases, TEMPEST emission
attacks, laser microphones and epic bugs, like the Great Seal bug, may
be more effective...

YSMV! :)

All the best,
Jacob



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