

What Your Cell Phone Can't Tell the Police - gbl08ma
http://www.newyorker.com/online/blogs/newsdesk/2014/06/what-your-cell-phone-cant-tell-the-police.html?utm_source=digg&utm_medium=diggtwitter

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hello_there
The article describes some circumstances under which a cell phone can be more
precisely located.

> Similarly, if you make an emergency 911 call, your company will use three
> towers to triangulate your location; if you’re using a smartphone, it will
> use G.P.S. to pinpoint where you are. If you’re the target of an ongoing
> investigation and law-enforcement agencies want to track you, they can ask a
> phone company to “ping” your phone in real time.

The “ping” part caught my attention: this sounds like a method that actively
queries the phone in a way that could be detected by the end user. Does anyone
know if this is possible to detect? Would, for example, an Android phone allow
a developer to write an app that could detect this and notify the user?

~~~
13throwaway
I'm really interested in a less-trackable cell phone, but until I read this
article, It didn't seem possible. I am really hoping a fully open source phone
comes to the market soon. It wouldn't have this ping "feature", it could
connect to the second or third closest tower, and it could completely shut off
cell when on wifi.

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gaius
Open source doesn't help, if you are using the hardware that has been
certified to connect to the public network. It could have anything in it. You
would need to start literally at the fab.

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stillsut
Just like the inmate in Texas executed, and (wrongfully?) convicted on pseudo-
science arson investigation evidence.

I wonder what other type of crap is putting innocent people in jail? Maybe
more interesting question: how can a jury of average citizens be expected to
weigh this evidence when even FBI task forces can't completely figure it out?

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A_COMPUTER
>I wonder what other type of crap is putting innocent people in jail?

Rhetorical question? It's polygraph, drug sniffing dogs and breathalyzer.
There was a court case a while back about drug sniffing dogs that presented
the empirically demonstrated fact that the dogs present false positives all
the time; but the judges concluded that it resulted in so many convictions
that it would be a disaster to prevent their being evidence in court
(analogous to witch dunkings, I suppose.) And breathalyzers are electronic
devices whose source code is not auditable because the it is a "trade secret."
Convicted by breathalyzer result? Can't challenge the black box's findings.

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stephen_g
Do they convict based on a breathalyser reading alone in the US? I'm fairly
sure that in my country/state, the breathalyser can only provide probable
cause for them to do a blood test.

Also, how could sniffer dogs provide evidence for court? Surely they couldn't
convict without actually finding drugs?

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judk
Dogs are used to (fraudulently) excuse otherwise-illegal searches, but
otherwise evidence is same as otherwise.

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giancarlostoro
If all they have is location on a phone, that could also place other people in
the area though. But I guess, that's irrelevant. There's also the chance that
the murderer didn't carry their cell phone in the area whatsoever. I mean who
goes and murders someone and talks on their phone at the same time anyway?

~~~
spacehome
Lots of people, it turns out. Murder is a pretty irrational act to commit, so
I wouldn't expect murderers to display tons of foresight in planning.

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secabeen
This is why I generally like having features like GPS and Google location
tracking turned on. The police, government and large corporations already have
access to lousy data they will happily use to my detriment. If I have better
data, I can use it to my benefit.

~~~
laggyluke
The problem is that you can spoof Google location tracking and other systems
that actively report your location, but you can't (AFAIK) spoof your cellular
tower data.

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keyme
I don't know the level of difficulty involved in the former, but "spoofing"
cell data is possible by making the phone connect to sub-optimal towers. This
would cost you service quality and battery life, but you'd "appear" elsewhere.
This requires reversing and patching proprietary software, though.

~~~
Tuna-Fish
The cell towers save the round trip time of each ping. This means that even if
you connect to a far-away cell tower (which you can actually do just fine with
a long metal cylinder and a kettle lid, no need to mess with software), they
will be able to tell you were not near the tower in question.

~~~
robryk
Is the RTT really dominated by lightspeed delays and not processing in the
phone?

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Tuna-Fish
The processing in the phone can be reliably removed from the equation using
simple statistical methods.

~~~
keyme
Not unless a software patch on the phone introduces significant random
variances into the RTT. But yeah, there will be no pretty way to make the
network "think" you are actually near another far away tower. I bet, however,
that this is still possible using a vulnerability in the "ping" method itself,
like not sending a random nonce for authentication of responses (so that I
couldn't send the "pong" before receiving the ping).

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tantalor
This reads like a textbook example of "circumstantial evidence".

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DrStalker
"Circumstantial evidence" is any evidence other than a direct eyewitness of
the crime; if your fingerprints are at the crime scene, your shirt is covered
in the victims blood, you're carrying a gun that matches the bullets pulled
out of the victim and a busload of tourists filmed you leaving the victim's
building after gunshots were heard that's all circumstantial. Those things all
infer guilt, but don't directly prove it.

~~~
AnthonyMouse
> Those things all infer guilt, but don't directly prove it.

Which is why they're all so untrustworthy. Take your example: If what actually
happened is that you were sitting next to your friend having a beer when a
madman came in and shot your friend, and then you wrestled the gun away from
the madman and barely escaped with your life, you would get all that same
"evidence."

~~~
stan_rogers
Given that there are only two kinds of evidence, _circumstantial_ and
_eyewitness_ , and that eyewitness evidence is almost useless unless the
witness knows the accused (and was close enough and had a good-enough look not
to be mistaken) or the accused was apprehended _in flagrante delicto_ , bet on
circumstantial either way (to convict or to clear). Dismissing circumstantial
evidence means that if you sort of resemble the impression that an eyewitness
had of the perpetrator and were wearing clothes that were "brown, or maybe
blue... it was kinda dark" and the testimony of that eyewitness just, you
know, feels more credible than the seventeen people who will swear up and down
that you were elsewhere at the time, then the more objective (but "merely
circumstantial") evidence that can reliably place you elsewhere isn't going to
be a whole lot of help to you.

~~~
AnthonyMouse
I'm not saying that eyewitness testimony is automatically better. It's
generally pretty terrible, and people have all kinds of different incentives
to lie on top of being mistaken.

The underlying problem is that we're making decisions that change the course
of lives based on weak evidence of any type. Nobody wants to actually follow
"beyond a reasonable doubt" because it would mean too low a conviction rate,
so instead we suffer too high a false conviction rate.

But you're also confusing what classifies as one type of evidence or the
other. The seventeen people who swear you were somewhere else are eyewitnesses
to your alibi. In addition, circumstantial evidence is extremely useful to
acquit, because although proof that you _could have_ committed the crime
doesn't prove that you did, proof that you _could not have_ committed the
crime does prove that you didn't. The prosecutor has a tough job, and they're
supposed to, because they're proposing to lock a citizen in a cage for a
number of years. That's a thing that should happen a lot less often than it
does.

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hamiltonkibbe
"A GPS transmitter" ... "Seize the GPS chip" an accurate description of
technology is always nice

