
How License-Plate Scanners Are Eroding Our Privacy - jamesbritt
http://www.popularmechanics.com/cars/news/industry/how-license-plate-scanners-are-eroding-our-privacy-16172152?click=pp
======
alpeb
This reminded me of this pic, trying to sql-inject a license plate system:
[http://landofthefreeish.com/wp-
content/uploads/2010/03/sql-i...](http://landofthefreeish.com/wp-
content/uploads/2010/03/sql-injection-plate.jpg)

~~~
user24
That's more specific SQL than a simple gag would require... story?

~~~
toomuchtodo
[http://gizmodo.com/5498412/sql-injection-license-plate-
hopes...](http://gizmodo.com/5498412/sql-injection-license-plate-hopes-to-
foil-euro-traffic-cameras)

------
Houshalter
License plate scanners are pretty cool technology-wise. It's amazing machine
vision has advanced that much. I was under the impression these were being
used to search for specific license plates though. Like a stolen car or the
car of a fugitive. I didn't realize they were storing every single license
plate recorded into a giant database. That is more concerning.

~~~
adolph
It would be an impressive feat of syncing for each license plate monitoring
node to receive a constantly updated list of license plates of interest.

~~~
Houshalter
Not really they already have some kind of computer with database access in
every cop car I believe. And the worst case is you just update it daily or
manually enter wanted plates in if it's urgent.

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ghshephard
This certainly puts Steve Jobs tradition of leasing a new car every 6 months
to avoid having to put a license plate on his car in a new light.

[1]
[http://appleinsider.com/articles/11/10/27/steve_jobs_stayed_...](http://appleinsider.com/articles/11/10/27/steve_jobs_stayed_tag_less_by_leasing_a_new_car_every_six_months)

------
A1kmm
The crux of the argument which comes up from the 'apologists' for this type of
thing extends from a different understanding of the axioms of privacy to
everyone else.

Let p(x) be a proposition that means that doing x is a violation of someone's
expectation of privacy.

Some people seem to assume that (not p(x)) and (not p(y)) implies that not p(x
union y). In other words, the assumption is that if x is not a violation of
someone's expectation of privacy, and doing y is not a violation of someone's
expectation of privacy, then doing both x and y is also not a violation of
someone's expectation of privacy.

However, the 'mosaic theory' suggests that the above assumption is not valid -
doing x and y individually might be perfectly reasonable, but doing both could
be a violation of someone's expectation of privacy.

------
auctiontheory
Here's what the police in my town are doing:
[http://www.almanacnews.com/news/2013/06/04/the-unfiring-
of-a...](http://www.almanacnews.com/news/2013/06/04/the-unfiring-of-a-menlo-
park-police-officer)

~~~
yid
From TFA: "...said the Menlo Park police department violated his client's
rights during the internal affairs investigation"

I actually support his getting his job back, because it seems to have been
found that the police department overstepped their boundaries in their
investigation of him. If that is indeed true, then it's imperative that any
illegal evidence against him should be discarded.

~~~
auctiontheory
At some level, if you have enough defense lawyers, it becomes literally
impossible to conduct a detailed investigation without forgetting to dot an i
or cross a t somewhere.

I don't know whether they violated his rights or not, but it's pretty clear
from the reporting (all of which I've read, since he makes $150K as my
neighborhood cop) that he's guilty in the pure sense of "he did it." And they
originally discovered him in some other context - not while illegally pursuing
him. (While "they" continue to illegally tap your phone, and your emails, and
mine.)

~~~
bmelton
There's legal theory around this, and it's fairly well established, though
often somewhat murky. The concept is "inevitable discovery".

The defense attorney can bring up claims that the evidence was ill-gotten, and
if the claim is upheld, then the judge can throw out everything gained
afterward, unless they can prove that it would have been discovered unrelated
to the ill-gotten loot.

For example, if a police officer searches your home without a warrant and
finds the murder weapon, that murder weapon ceases to exist, legally, and the
suspect will likely get away scot free.

However, if a different officer pulls him over for a DUI a week later, not as
a result of information provided by the unlawful search, and finds blood in
the back seat of the car, which leads to an arrest, prosecution could claim
that they would have obtained a warrant to his home that would then have
likely surfaced the murder weapon.

Edit, all that was fairly random rambling, re-reading it in context, but what
I meant to say was that I agree, and that his confession ought to be enough
grounds to keep his termination permanent.

------
eliteraspberrie
There is very little which is less private than a license plate. They are
explicitly designed to be as public as possible, as they should be.

~~~
greenyoda
I think that's totally missing the point of the article. The license plates
are being used to track where every person goes over a long period of time,
which can uncover some very private information about people, like whether the
person is cheating on their spouse, or sees a psychiatrist on a weekly basis.

And yes, you can find this out just by physically following someone wherever
they go, but since that's impractical to do on a mass scale, it's not likely
to be done for people who aren't targets of specific criminal investigations.
License plate scanning collects this personal information indiscriminately
about totally innocent people.

And this information is likely to be abused by people in positions of power,
just like existing records about people are. I can't count how many times have
I've heard about cops getting in trouble for running unauthorized database
searches on ex-girlfriends, etc. Detailed data about a person's every movement
would be even more tempting to abuse.

~~~
diminoten
You're taking actions in public, of course it's not private. Where do we get
this idea that, not only do we have a right to privacy, but we have a right to
privacy everywhere, all the time?

As for potential for abuse, guns can be abused too - that doesn't mean guns
aren't allowed at all. Or if your country does ban guns, think of something
else that might be abused but is allowed anyway.

Just because something could be abused doesn't mean that's a valid reason for
not doing that thing.

~~~
angersock
When one is in public, out of eyesight of any non-friendlies, one does indeed
expect privacy.

When one is moving across several disparate geographical locations, there is
indeed an expectation of privacy.

The simple "hurf durf you're in public ergo no privacy ever" argument is
horseshit, to put it bluntly.

~~~
diminoten
I have a right to record when I see you. Everyone has that right. If you're
free to act, I'm free to record that act, assuming you've acted in public.

Also, what's "horseshit" about "you don't have privacy when you act in
public"? I'm not recording your conversations as you're in public, only what
you do. Why is that horseshit?

~~~
moutarde
> Why is that horseshit?

Because historically (and also legally) the bounds between what is private and
public have been defined by what was _plausible_ at the time, not by what was
_hypothetically_ possible.

We know live in a world were what used to a be a hypothetical dream (or
science fiction novel) has now become the mundane. The law can either adapt
(via judicial rulings), be changed by voters or become an absurd anachronism
that's good for nothing but justifying invasive surveillance.

~~~
diminoten
History and legality are not relevant morally.

It's _morally_ wrong to try and stop me from automatically recording the
license plates of the people who drive by my house.

~~~
maxerickson
But you recording by your house isn't that interesting.

It is more complicated when you start talking about whether you should sell
derivations of those recordings or someone aggregating the recordings made by
many people.

~~~
diminoten
It's not much more complicated. If I own properties throughout the city, and
at each of those properties I record every license plate that drives by, I'm
well within my rights to not only do that, but to aggregate that data and
supply it to others if they ask.

It's the exact same thing as CCTV, fundamentally. How can you construct an
argument that prevents me from doing _this_ without preventing many things we
already are okay with?

~~~
maxerickson
Legally, probably. Your final question sets a bad standard, present day
societal approval is only weak evidence (that is, lots of heinous shit has
been normative in various historical periods).

There is also the problem where you are talking about morality as if it is
clear cut and all settled.

Anyway, I'm pretty well in favor of trying to find a meaningful definition of
a space that exists between public and private, where shared space activities
are not just a free for all. Mostly, because I think I would/will be more
comfortable in shared spaces if I can expect that other people will mostly
have some respect for my wish to not be followed around with technology.

(I would argue this space exists, it's plenty easy to irritate someone by
'getting in their face' in public. This is them expressing strident
disapproval of your behavior...)

~~~
diminoten
What is that argument, specifically? So far all I've heard is "this is wrong",
not "this is wrong because of x".

The _only_ point anyone's been able to make is that it could possibly be
abused, but frankly, _everything_ the government can do can be abused. You'll
need more than "it could be abused" to argue against it.

~~~
maxerickson
I'm arguing that it makes me uncomfortable and that this discomfort will be
widely shared. Go ahead and disagree that morality is something different than
that if you want. You are also welcome to think that is weak sauce (but then
go ahead and make a habit of making strangers uncomfortable in public and see
how that serves you).

~~~
diminoten
I hope you realize this isn't a rational argument.

~~~
maxerickson
Go ahead and lay out the one true rational argument for morality then (you
brought up morality way up thread there...).

~~~
diminoten
Recording and documenting where you go in no way hinders or interferes with
your freedom of action, therefore I retain my right to freedom of action in
doing so.

I don't have a right to go into a place where you have privacy. If you come
out of a private place, or act in a way that is public, I have every right in
the world to track you.

------
cjaredrun
What about having some sort of UV LED light that would shine above or below
your plates so as to obscure any cameras?

~~~
grecy
You can spray your plate with hair spray or clear gloss paint too - the camera
flash reflects and the photo is not usable.

It's illegal, of course.

I much prefer the idea of getting a custom plate that's something like
00000O0000 or 1111l11111 etc. depending on the font.

~~~
Amadou
_You can spray your plate with hair spray or clear gloss paint too - the
camera flash reflects and the photo is not usable._

It doesn't work. Mythbusters tried it.

[http://www.forbes.com/sites/adamtanner/2013/07/10/data-
broke...](http://www.forbes.com/sites/adamtanner/2013/07/10/data-broker-
offers-new-service-showing-where-they-have-spotted-your-car/)

~~~
grecy
Ha. We did it, and the photo taken by our camera with a flash showed nothing
but bright reflection on the plate...

~~~
Amadou
Did you use the same camera design as the speed & red-light cams do?

Also, the plate readers, they don't even use flashes. They are essentially
video cameras.

~~~
grecy
> Did you use the same camera design as the speed & red-light cams do?

We didn't.

In Australia, at least, red light cameras _are_ cameras, and they do have a
flash (you can see it go off). The plate readers on the freeways for tolls are
more like video cameras.

------
psc
What this article doesn't mention is that this data isn't only for cops,
anyone should be able to see license plate records. Milage may vary, but since
this is government data, something along the lines of a FOIA request should
get you huge files with license plates, coordinates, and times. Some police
departments may be more stubborn, but under current laws this data should
pretty much be public.

For example here's data from Minneapolis (with anonymized license plates):
[https://github.com/johnschrom/Minneapolis-ALPR-
Data](https://github.com/johnschrom/Minneapolis-ALPR-Data)

Privacy concerns aside, there's definitely something really cool about so much
data.

------
MikeTLive
historically the use of license plates were fought because of the potential to
track the coming and going of american citizens. however, it was decided that
it was not possible to do such tracking so they were allowed. the error is
that provisions were not made that when such fears were realized the use of
such plates should be revoked.

------
brndnmtthws
Bicycle. Problem solved.

~~~
dmourati
I was going to say just this. I suppose it would be possible for states to
require bicycle license plates. I have yet to see that though.

~~~
noarchy
I know of some Canadian jurisdictions that used to require bicycle licenses.
Toronto was one, until the 1950s.

I can't imagine a license scheme being repealed these days, as these things
are all about the fees that can be collected, as well as the feature-creep
that bureaucrats can promote. A drivers' license today goes well beyond
driving, now, in its various official (and unofficial) uses.

------
jgoodwin
I think there is a mathematical theory here people should become acquainted
with -- differential privacy. So far it has found use in the context of a
large data set, e.g. search engine query logs, to try to determine how
invasive a statistical summary or release of only partly obfuscated data would
be.

Like calculus, it has a sort of epsilon/delta construct -- given a
differential privacy concern epsilon, under what circumstances (how tight a
bound on delta) do I need to prevent that.

[http://en.wikipedia.org/wiki/Differential_privacy](http://en.wikipedia.org/wiki/Differential_privacy)

Perhaps this theory could quantify the intuition that while it's ok to snap my
license plate now and then (very little differential privacy loss on my part),
enough times and it becomes invasive, and dreadfully so.

This puts some teeth into the vague talk about a mosaic theory. The key idea
is whether the aggregate information in the data set can triangulate you, to
within say 10000 persons (not much privacy invation), or 100 (quite a bit).
There seems to be a tipping point around clusters of 100-1000 persons or so,
that is the typical size of small organizations or groups of people, such as
churches and schools.

Now, as an application: license plates are nearly unique identifiers and the
attacker has a database of who's who for all intents and purposes, so it is
little different from asking everyone for their ID just because they are on
the street. That's illegal by the way, even for the police.

The argument that was formerly deployed here is that using a vehicle on public
roadways was a privilege that cost you natural expectation of privacy (non-
intrusion) in public places.

The real crux of the issue here is that the public-private tradeoff was once
predicated on the individual (the individual atom has protection, because data
collection is sparse, so tagging the individual but not the path was
meaningful). Now the data collection is dense, and even single particle tracks
become visible.

If you think in terms of fluid mechanics, there's a sort of Euler view /
Lagrange view here (as there is with tagged dollar particles and tagged
wallets or accounts).

That is, tracking individuals and tracking their paths become duals of each
other, if the data collection is dense enough. It doesn't matter whether the
item tracked is the tagged individual, or the flows and transactions -- either
way, complete reconstruction of the system becomes possible.

With any data set, there is a sort of 'phase transition' in its size, where
you suddenly can see the underlying trajectories of all the tagged particles.
Things that made perfect sense when data collection was sparse, just as
allowing the police to jot down you license number and chase you with a
bicycle, turn into totalitarian surveillance when the observations become
dense enough -- in a way we can quantify in terms of a sudden jump in
information gain that goes from nearly complete ignorance of where people are
and what they are doing (the former phase), to near complete knowledge of
everything. Very much like percolation theory.

~~~
Amadou
_asking everyone for their ID just because they are on the street. That 's
illegal by the way, even for the police._

That is not illegal at all. Anyone can _ask_ for ID, including the police.
Doesn't mean you have to give it to them. In the case of the police, refusing
to show your ID can't be used as cause to arrest you. But they can still ask
for it.

~~~
VexXtreme
In a lot of countries it's certainly grounds for arrest as carrying a
government issued ID is mandatory.

------
jrockway
You already gave up your rights when you agreed to "implied consent". This one
isn't even in the Constitution.

