
Why Snowden Asked Visitors in Hong Kong to Refrigerate Their Phones - llamataboot
http://thelede.blogs.nytimes.com/2013/06/25/why-snowdens-visitors-put-their-phones-in-the-fridge/?_r=0
======
tszyn
I just put my phone in the refrigerator and called it -- works perfectly. Then
I tried the same thing with a microwave oven (following pilsetnieks's
suggestions) -- didn't even lose one bar on the signal indicator. It did kill
the Wi-Fi reception, so clearly the oven is blocking the 2.4 GHz frequency as
it should.

Edit: Also tried a cookie can. (And anti-static bags -- see below.) Faraday
cage my ass.

Clarification: I use a Nokia. Maybe the technique works only on iPhones? I've
heard they have some reception issues.

~~~
flog
Got an anti-static bag to try, as others suggested? Would be interested in
your result.

~~~
cyanoacry
An anti-static bag (even the metallized type) probably won't be the best idea.
Faraday cages depend on the conductivity of the outer shield to exclude
electric fields from the inside, but anti-static bags aren't very conductive
(100k-10G ohm square resistivity[1]).

You might even be better off wrapping the phone in aluminium foil, but the
problem is then going to be ensuring that all seams in the "cage" are actually
conductive.

[1][http://www.esdjournal.com/techpapr/ryne/esdbags.htm](http://www.esdjournal.com/techpapr/ryne/esdbags.htm)

------
kintamanimatt
I hope the fridge was off.

A fridge will act as a fantastic acoustic shield but probably not a
functioning Faraday cage. I think this blog post has taken a few artistic
liberties in suggesting its use was as a Faraday cage, especially as the
article she links to doesn't mention the fridge's purpose as a Faraday cage.

Assuming this story isn't stretched and exaggerated (I have a hard time
believing it isn't) and the fridge was on, this could be a fast way to trigger
condensation to form inside the phone when the device is removed back into a
warmer environment, depending on the ambient humidity. I just wouldn't dream
of putting my phone in a cold fridge for anything other than the briefest time
for this reason.

~~~
jevinskie
Why not on? Wouldn't the compressor improve the situation by adding background
noise? Also if condensation is a concern you can put the phones in a plastic
bag.

~~~
kintamanimatt
When a fridge is on it usually means it's cold! If it's off (and has been for
a while) it could be expected to be around room temperature, eliminating the
issue of condensation.

The compressor isn't on all the time. It turns on intermittently when the
temperature inside the fridge exceeds a certain threshold. It would be
unlikely of much use most of the time.

Putting the phones in a bag does nothing to solve the issue of condensation.
What happens is the phones would cool down substantially in the fridge. When
they're removed, the cold surfaces (inside and out) would cause moisture in
the warmer air to condense into water droplets, possibly causing issues with
the battery and the other circuitry. Hong Kong is quite a humid place and it
appears that he was at an acquaintance's home at the time of the frigid phone
incident. It's unclear how well air conditioned this acquaintance's home was,
which could lead to some especially nasty condensation issues. It's also
unlikely this acquaintance's fridge would have been brought up to room
temperature just for the sole purpose of storing phones for a couple of hours.
This is why I'm inclined to believe the anecdote is BS.

~~~
mturmon
"The compressor isn't on all the time. It turns on intermittently when the
temperature inside the fridge exceeds a certain threshold."

Modern, high-efficiency fridges have compressors that operate continuously.
It's more efficient than cycling. My fridge draws about 60 watts continuously.

It's still thermostatically controlled, of course, so if the doors are left
open, it will kick up higher.

~~~
kintamanimatt
I'm not exactly a fridge nerd but I had no idea such fridges existed and I'm
somewhat curious as to why it's more efficient than cycling. Perhaps it's the
ease of which to maintain a constant temperature, rather than a fluctuating
one?

What fridge do you have out of interest?

~~~
mturmon
I have an Electrolux.

Here's a report about variable-power compressors:

[http://www.panasonic.com/industrial/includes/pdf/invertercom...](http://www.panasonic.com/industrial/includes/pdf/invertercompressors-
improvingefficiency.pdf)

I was introduced to refrigeration nerdery by talking with a friend who designs
the cryocoolers for JWST
([http://www.jwst.nasa.gov/cryocooler.html](http://www.jwst.nasa.gov/cryocooler.html))
who nodded sagely and said "more efficient that way" when I mentioned my new
fridge did not cycle on/off. Now that's a fridge nerd!

------
rayiner
Slightly tangential story. My first assignment on my first job was building a
knockoff TEMPEST enclosure
([http://www.jammed.com/~jwa/tempest.html](http://www.jammed.com/~jwa/tempest.html))
to isolate spectrum measurement equipment. The original use of the enclosures
was (somewhat ironically given the article) the NSA's paranoia that foreign
intelligence would spy on government computers by picking up their EM
radiation.

So if you're worried about the government spying on your computers via RF and
want something more convenient than a fridge, drop me a line...

~~~
MWil
if you're feeling like a profiteer why don't you just start selling a faraday
cage phone case

~~~
rayiner
The real money is probably in building faraday rooms.

~~~
doctorstupid
You're right, there's lots of money being made by contractors in the faraday-
room business:
[http://en.wikipedia.org/wiki/Sensitive_Compartmented_Informa...](http://en.wikipedia.org/wiki/Sensitive_Compartmented_Information_Facility)

------
aplusbi
I used to develop nintendo DS games and once received a very memorable bug
report - something to the effect of "got error [error message] when playing
the game in a microwave".

We weren't handling lost wifi connections gracefully so the user would get the
wrong error message if their wifi dropped. The tester was simulating this by
placing the DS in a microwave.

------
swamp40
Someone once came to us and asked us to design a wireless thermometer for a
freezer. We told them it wouldn't work, because the freezer would act like a
Faraday cage. Then they showed us a similar device that worked just fine.
Embarrassing.

We test a production device here that makes a LOT of noise, and we put it
inside a mini-fridge to dampen the noise so it doesn't drive the testers
crazy. Works quite well. I doubt you'd pick up any outside conversation if you
were trying to eavesdrop (especially if the freezer was humming).

------
pilsetnieks
Shouldn't a microwave oven be the perfect household Faraday cage? It certainly
has the shielding to contain 2.4 GHz waves, so the 800, 900, 1800, 1900 MHz
cannot be that far off.

~~~
marshray
Less soundproofing.

~~~
human_error
How about putting phones inside the microwave and then putting microwave
inside the fridge?

~~~
marshray
I favor putting the phone in the martini shaker, and the shaker inside the
dishwasher while washing a big load of clanky dishes.

------
DanielBMarkham
Yeah, that's not going to work as a Faraday Cage. I guess you'd have to put
the cellphone in the microwave, _then_ put the microwave in the refrigerator.
That's going to look weird. :)

I used to do a bunch of micro-sites -- small websites targeted around specific
topics. One I did a few years back was [http://gps-cell-phone-
tracking.net/](http://gps-cell-phone-tracking.net/)

I really learned a lot setting that site up, and it was one of the reasons I
became such a privacy freak. Our cell phones are basically tracking devices
the government monitors which we happily adorn to our bodies each day. Weird.

To get to my point, one of the questions on the site was whether your phone
could be tracked, either location or having the audio monitored, without your
knowing it. Location is easy -- yes. Audio was a bit weirder. Obviously you'd
have to install an app, and who would want to do that?

Then I learned that cell providers will "help" governments by putting tracking
code inside the auto-update of the phone. They can even push it at night and
have it install without your having any knowledge at all.

As far as I know, pulling the battery still kills things, but then somebody
said most phones have a dual battery to keep the memory refreshed. Somebody
even said something about the possibility of "illuminating" phones from a
distance and picking up audio that way. Of course, "somebody said" doesn't
count for much, and with all the secrecy in place good luck figuring out what
is what.

Fun stuff. Since the micro-site business didn't take off, maybe there's a
future in selling tin-foil hats?

------
quackerhacker
I won't speculate on eavesdropping since I haven't tested this, but what I
hear when I heard his method is more of the security risk that he could
possibly be pinpointed. A red flag would go up for me, hearing multiple people
(the lawyers) clustering to one location.

Smartphones are a beacon of constant info...GPS and signal pinging can get
your coordinates (at least general area), and Wifi can triangulate the
position [0]. Cameras and microphones are just icing and still require a
device to be compromised, whereas signals, require carrier network
access...which is what PRISM revealed [1].

[0] [http://thenextweb.com/apple/2013/03/26/what-exactly-
wifislam...](http://thenextweb.com/apple/2013/03/26/what-exactly-wifislam-is-
and-why-apple-acquired-it/)

[1] [http://news.cnet.com/8301-1009_3-57589100-83/nsa-
whistleblow...](http://news.cnet.com/8301-1009_3-57589100-83/nsa-
whistleblower-u.s-has-been-hacking-into-china-hong-kong/)

------
at-fates-hands
Verizon uses an 700MHZ and 1700/2100MHZ signal on their 4G network which will
give you incredible penetration. People brag about how you can be in a
basement of an office building (lots more concrete and steel than a
refrigerator) and still get great reception.

[http://en.wikipedia.org/wiki/Verizon_Wireless#Radio_Frequenc...](http://en.wikipedia.org/wiki/Verizon_Wireless#Radio_Frequency_Summary)

If they were using a carrier in Hong Kong, most of the carriers use a higher
spectrum, usually around the 1800-2100MHZ range. While it doesn't give you
great penetration in buildings like the lower frequencies Verizon use, I'm
guessing the overall density of the towers is significant which would help
this issue.

If he said they want into the basement of a building THEN put the phones in
the refrigerator, it would be a little more believable. Just putting it in the
refrigerator probably won't do a lot to block the signal.

~~~
rayiner
Its not the mass of concrete and steel, but the faraday cage effect of a
continuous closed loop of conductive material.

Though aas has been pointed out, a fridge probably isn't electrically
continuous at the door gasket. Depending on the construction, you could
replace the rubber gasket witha rubber core metal mesh gasket.

------
hawkharris
I usually tell the lawyers to put the phones in their a--. It's not more
effective, per se, but it's certainly funnier.

~~~
hawkharris
Okay, I admit that I deserve a downvote for this...But I couldn't resist :)

------
leke
I used to work as a phone tester and sometimes had to test things while the
phone was in a unreceivable location. I tried many things, like a safe,
fridge, cookie jar etc, but the only thing that worked was wrapping the phone
in 2 or 3 layers of tin foil.

------
CamperBob2
Hard to imagine a worse Faraday cage than a refrigerator. The rubber seal
would create a nice slot antenna running 3/4 of the way around one side.

The microwave oven would be much, much better.

~~~
jychang
The rubber seal is a better audio seal though, which is more important.

~~~
CamperBob2
Probably best to put the phones in the microwave, and leave the microwave in
the bathroom with the shower running to create masking noise.

Or just turn on the microwave for a few seconds. :)

~~~
snogglethorpe
Wrap the phones in tinfoil, put the wrapped phones inside the stainless-steel
martini shaker (see other thread), put the martini shaker inside a microwave,
put the microwave inside a refrigerator, and put the refrigerator in the
bathtub.

Now turn everything on "high", including the shower ("hot & steamy"), and run.

Snowden's guests will have done that a while ago of course...

------
gojomo
We need to crank our paranoic creativity up to 11, people.

The fridge itself had a false back. Snowden's associates in SPECTRE/Wikileaks
then used their covert physical access to the phones, for the duration of the
dinner, to copy the phones' contents and install new malware.

Now, they know what the lawyers know -- including whether any are
double/triple/etc-agents.

~~~
reeses
Jeez, I missed this when I posted my reply. It looks as if we're the only two
paranoid enough to see the danger and stupid enough to point it out and draw
attention to ourselves.

I'm sleeping in the bunker tonight.

------
alan_cx
This is absolutely NOT a piece designed to make Snowden look slightly odd.

~~~
achughes
Actually I thought the article put him in a better light than most of the
other pieces about him. It makes him out to be more in tune with the ways the
gov could track him. If they wanted to smear him then NYT could just come out
with a short piece saying "Snowden made his Lawyers put their Phones in the
Fridge", and then just spend the rest of the article speculating about his
growing paranoia and questioning the decision.

Instead they explained the logic behind the seemingly unreasonable request.
How is that being malicious?

~~~
alan_cx
I'm from the UK. We have tabloids. They will take a fact like (made up
example) Snowden wanted all phones turned off, and simply make up the rest. 1)
to demonize the subject, and 2) to put a more sexy sounding story in the
paper. So, my natural default is to hope to believe the simplest "fact" in the
story, if that.

Maybe you have faith in your newspapers, and to be totally honest I don't
actually know how Americans feel about their news papers. But you do have
Murdoch floating around, so Americans are being manipulated somewhere. But I
sure as hell dont take them at their word. For me, newspapers are as accurate
as "the internet".

But to me, that read like a slightly more sophisticated that a UK tabloid
smear job.

I do how ever accept that my UK perspective on the press might well be very
different to a US one.

------
hawkharris
Comments on this story illustrate the difference between Hacker News and other
news sites. Most people say "That's cool" or maybe share links related to the
research. People on HN said, "Okay, now that all our phones are locked in the
freezer, let's compare data." :)

------
PencilAndPaper
So the mic in your phone can be used as a bug when you arent using it?

~~~
zalew
yes

[http://news.cnet.com/FBI-taps-cell-phone-mic-as-
eavesdroppin...](http://news.cnet.com/FBI-taps-cell-phone-mic-as-
eavesdropping-tool/2100-1029_3-6140191.html)

[http://hackaday.com/2009/09/14/disabling-your-cell-phones-
mi...](http://hackaday.com/2009/09/14/disabling-your-cell-phones-mic-for-
security/)

~~~
finnw
Has anyone ever actually found NSA spyware on a feature phone?

------
EGreg
I am pretty sure that if someone wanted to they could easily construct a
faraday cage, instead of using a fridge!

[http://www.disaster-survival-resources.com/faraday-
cage.html](http://www.disaster-survival-resources.com/faraday-cage.html)

By the way, it's also useful against solar flares...

~~~
rayiner
If you want something NSA scale, you can do better than that. I used to use
Copper-Beryllium mesh and gaskets ([http://www.sealingdevices.com/metal-emi-
gaskets-and-becu-ber...](http://www.sealingdevices.com/metal-emi-gaskets-and-
becu-beryllium-copper-springfingers)). Choose mesh size based on the
frequencies you expect to deal with (and harmonics).

If you want to keep your computer in there you also have to be careful
designing the ports for wires coming in/out.

~~~
EGreg
Why do you say that about the ports?

~~~
kefka
Every wire is also an antenna that is attenuated to the appropriate
frequencies related to the length of the wire.

A 2 meter cable also receives on 144 MHz any spurious signals (amateur radio
band). If that was an EMP, it would send a voltage spike up the port and blow
out whatever it hit.

~~~
EGreg
Oh, I thought you meant that the faraday cage would interfere with the wires
conducting electrical signals

------
Snowda
I bought some EM radiation blocking cloth from LessEMF and stitched it to the
inside pocket of my jacket which I rarely use. If I'm feeling paranoid (or if
I'm not arsed to turn on airplane mode to save battery) I just put it in that
pocket instead of the normal one and zero communications can get in
(especially my mother)

~~~
GoodIntentions
curious. Do you notice decreased battery life if you do this? I would think
you would chew through battery like a mofo if you block carrier, but leave the
phone on. It's gonna try hard to hit a tower non-stop, I expect.

~~~
crdoconnor
My phone does. If I ever take it to an area with zero reception and forget to
turn on airplane mode, the battery dies in 2-3 hours.

------
jstalin
I just tried putting my cellphone in a stainless steel martini shaker and it
definitely worked as a faraday cage.

~~~
e12e
That's some real James Bond shit, right there!

(sorry, couldn't resist :)

------
betterunix
My initial reaction was that the phones-in-the-fridge rule was meant to muffle
sounds. Can anyone comment on whether or not a phone in a fridge can pick up
sounds from the room the fridge is in?

~~~
cheald
Seems like the kind of thing that you could test empirically.

------
keerthiko
Isn't just wrapping the phone in aluminium foil (as many layers as needed to
make you feel comfortable) enough to act as a faraday cage? And leaves the
cellphone still portable, you can unwrap if/when needed. And then bury it in a
pile of clothes in another room (as the article suggests somewhere) for the
soundproofing. The refrigerator I feel serves neither of these purposes well
(as mentioned in this discussion), and ruins everything when it's time to make
a sandwich.

~~~
gweinberg
I just tested this, aluminum foil does seem to block signals coming to my
phone. At least, the wrapped cell phone doesn't ring when I call it with my
house phone. The wifi signals may still be getting through, I don't know.

------
flog
So given that Snowden would be in the know about such things, this would
confirm the legend of phones being remotely controlled for listening devices.

Were there any iPhones in the fridge?

~~~
rit
Why would it confirm it? "Correlation does not imply causation".

He may be pulled in by the same rumours as everyone else and being overly
cautious. Just because he does this doesn't indicate he has confirmed or
denied the existence of a slave microphone bug.

Just that he believes strongly enough in the possibility to be cautious.

~~~
Jach
Correlation may not boolean-logically imply causation, but it's evidence of
causation.
[http://oyhus.no/CorrelationAndCausation.html](http://oyhus.no/CorrelationAndCausation.html)

The actual cases I've seen (some linked on this page) are of specifically
targeted individuals having their phone receive a command to turn into a
bugged phone. I don't think all phones are bugged by default. This fits with
Snowden wanting people around him to sound-proof their phones as they might be
targeted.

------
chrsstrm
You would think instead of stashing them in the fridge, he would ask visitors
to not carry a GPS receiver right into his hideout. We complain about the gov
possibly bugging and tracking us, yet we do it to ourselves willfully almost
24/7.

------
semiprivate
The real answer: he looked around the house and decided it was the best place.
lots of metal, and a hum to drown out noise.

The NSA leak was important enough, we don't need to pretend like he's some
kind of privacy McGuyver.

------
planetjones
Couldn't he have just put the phones in airsafe mode? Plus if they were
tracking the lawyers then they'd probably have seen them arriving at the
location even if the signals went off when they arrived.

------
doctorstupid
Obama has his own Faraday tent: [http://www.bbc.co.uk/news/world-us-
canada-12810675](http://www.bbc.co.uk/news/world-us-canada-12810675)

------
Bosence
Would taking the battery out simply suffice, too?

~~~
joelrunyon
They address this at the bottom of the article (read the whole thing).

 _Battery removal can be equally deceptive. Even once one figures out how to
extract the primary battery, there may be additional power sources within the
apparatus. “Some phones use an additional battery for memory management; it’s
unclear whether this battery could be used by logging and /or tracking systems
such as Carrier IQ,” Mr. Harvey explained, referring to software that monitors
mobile phone users._

~~~
neurotech1
I suspect the OP is claiming that Carrier IQ tracking could still be active,
in low-power/sleep modes, that still could represent a privacy risk if the
battery is removed. When the battery is re-inserted and/or the phone is turned
on, then the data is transmitted to the cell tower, then Carrier IQ servers.

~~~
tmzt
What would that be collecting when the main application processor and baseband
processors are not powered? The battery referenced in the article is likely to
backup a RAM chip and isn't even used in most modern phone/smartphone designs,
which use Flash EEPROMs instead. There have however been phones which have a
small internal battery powered by the external battery which has to be charged
to operate the radio.

------
kashnikov
An anti-static bag should work just as well.

