[HN Gopher] Spies can eavesdrop by watching a light bulb's vibra...
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Spies can eavesdrop by watching a light bulb's vibrations
Author : lelf
Score : 146 points
Date : 2020-07-26 22:22 UTC (1 days ago)
(HTM) web link (www.wired.com)
(TXT) w3m dump (www.wired.com)
| imglorp wrote:
| The article involves a remote device watching the light bulb but
| it would also make sense to think about devices in the room as
| well.
|
| Your device might have its microphone disabled, in hardware even,
| but I wonder if the ambient light sensor has enough gain to see
| audio frequency variations in room lighting. We already know hard
| drives and speakers and whatever else can act like mics for
| exfiltration...
| [deleted]
| codezero wrote:
| In college for a project I wanted to encode messages over small
| brightness variations in light bulbs. It's a pain to deal with
| AC, so I ended up doing it with a laser pointer. It turned out to
| be stupidly easy with a laser pointer and photodiode attached
| almost directly to a pair of PC speakers. All these devices have
| a +5v DC signal. I could attach my iPod headphones to the laser
| pointer directly, then the photodiode to the speakers, and boom,
| music at about 100 yards, with almost no quality decrease, though
| I didn't do anything quantitative :)
|
| I've always wondered what places communication started getting
| hidden since we went online and no longer rely on things like
| numbers stations or drop boxes (though I assume dead drops still
| exist)
| miahi wrote:
| You can also send the sound via the laser directly to a MEMS
| microphone, if it's exposed:
| https://www.wired.com/story/lasers-hack-amazon-echo-google-h...
| amatecha wrote:
| K what? That's amazing! Apparently I need to learn more about
| lasers.... haha :) I guess it's pretty "fragile" since the
| slightest misalignment of the source laser & destination sensor
| would mean a total loss of signal, right?
| wonderlg wrote:
| You'll probably also need to debug it often on warm summer
| evenings.
| dwohnitmok wrote:
| Given that the laser forms a spot, minor misalignments are
| very easy to debug (just line up the red spot with the sensor
| again). Also given a laser with sufficiently wide spread,
| minor misalignments would manifest themselves as volume loss.
|
| Not great if you don't have easy access, but reliable enough
| for e.g. a dorm room or a living room.
|
| This was a lab we did in an intro EE class in college and it
| worked wonders as a "whoa cool" demonstration with very basic
| EE knowledge required.
| codezero wrote:
| The other commenter is right, store bought lasers have a
| descent spread over a few dozen or hundreds of feet. And the
| signal is still pretty readable to the receiving photodiode.
| rorykoehler wrote:
| You should find out how the starlink network will communicate
| if you're worried about accuracy.
| panda88888 wrote:
| A long time ago back in college our team designed a free space
| optical gigabit digital link via laser diode and photodiode. We
| were transmitting I think 1 Gbps easily over maybe 50 meters.
| We didn't have enough time to polish the system or test faster
| speed because the sponsoring corporation took our design back
| to their RD group.
| dkarl wrote:
| Twenty years ago I worked at a place that had offices in
| buildings across the street from each other and had a laser
| network link between them in case the link through our ISP
| stopped working. I don't recall if we ever had to rely on it
| while I was working there, but I remember the guy in charge
| of monitoring it used to complain that it didn't work on
| foggy mornings. One end of the link was on the 21st floor,
| and we got fog at that level a lot more often at that height
| than at ground level.
| codezero wrote:
| I bet this was a microwave dish, super common to connect
| buildings with line of site., and prone to fog and weather
| :)
| vt240 wrote:
| The Wikipedia entry for FSO networking is pretty
| misleading. There have been commercial products on the
| market for quite a while.
| 2OEH8eoCRo0 wrote:
| Didn't anyone watch or read Clear and Present Danger? Laser
| microphone. This has been done for the past 40 years or so.
| kainer wrote:
| Those stories keep fascinating me, ever since I talked about
| side-channel attacks during my study times.
|
| Re-creating CRT images through walls, listening in on keystrokes
| through the electric wires of a building or learning about
| traffic patterns while observing network interface flashing LEDs.
|
| Just a fascinating world when you leave aside what they are aimed
| towards.
| helios_invictus wrote:
| This technology and technique has been known for a number of
| decades. Intelligence agency use a variety of counters to avoid
| this issue. SCIFs don't have windows for a reason. The standoff
| distance for intel buildings are far, and well monitored for
| similar reasons. Some facilties use double insulated glass with a
| randomized noise maker in the frame. Some corporate board rooms
| use similar technology and safe guards.
| Jestar342 wrote:
| A friend of mine had a side-gig at an electronics factory that
| used to fit/repair government printers, telegram, and fax
| machines in the 80s. When he first started he noted that the
| schematics said to double up the number of capacitors. When he
| raised this as a potential error in the schematic with his boss,
| he was told that it was quite deliberate and was there to stop
| giving away what was being printed by anyone measuring the power
| fluctuations. Feels kinda obvious now but when I first heard it I
| had a mini-mind-blown moment.
| polishdude20 wrote:
| That seems like a good way to make a piece of equipment just
| not work. The stuff inside the printers also probably relies on
| proper capacitor values.
| jstanley wrote:
| Seems unlikely. It's probably ~all digital, so I expect the
| capacitors are literally only there for filtering the power
| supply.
| monadic2 wrote:
| Pretty sure state intelligence has been doing this for decades,
| and we all know the laser-off-the-window pane trick by now.
|
| I'm much less worried about spies than I am about the powers
| directly around me, namely my own state and the large
| corporations that run society.
|
| I have no clue who greenlit this article but it seems starved for
| context not spoon-fed by the research team itself.
| kanobo wrote:
| Tomorrow's news: Privacy Lightbulbs that vibrate pre-recorded
| messages to throw these pesky spies off their trail is invented.
| turbonaut wrote:
| Whilst the suggestion is clearly not serious, having pre-
| recorded or even repeated random noise is akin to re-using a
| one time pad. Continued 'listening' - even long after the
| relevant conversation - could first be used to extract the fake
| noise and then from this the signal.
| kerkeslager wrote:
| Yeah. You can't just produce random white sound[1] to cover
| the signal either, because speech has enough redundancy to
| still communicate over a static-y soundscape. The term here
| is that white noise lacks "diffusion"--analogous to the ECB
| vulnerability (see the picture of the encrypted Linux penguin
| image on this page[2]). I can't think of a good way to
| provide diffusion for sound--a better cover might be to
| provide alternate signals, i.e. a few layers of random human
| sounds spoken in a deepfake-d version of the voice of the
| person speaking.
|
| I'm skeptical even this wouldn't have vulnerabilities
| however, as history has shown us that cryptography which has
| not been formally proven is often broken.
|
| [1] I'm using the word "sound" here to differentiate the
| noise in the auditory sense from noise in the "signal versus
| noise" sense.
|
| [2] https://en.wikipedia.org/wiki/Block_cipher_mode_of_operat
| ion...
| kanobo wrote:
| Would it be possible to use the tech in noise-cancelling
| headphones and put a tiny speaker that phase-cancels audio
| it hears to solve this issue? I'm asking as someone who
| knows very little about this.
| kerkeslager wrote:
| Well, it's definitely possible to do that but I'll make
| no claim that it would actually provide security. There's
| definitely some bleed-through with noise canceling (i.e.
| the beginning of sounds don't get canceled because the
| noise-canceling has a "reaction time"). It's probably
| better than nothing, but I would guess that a
| sophisticated-enough attacker could get around it.
|
| Again, I have no proof of concept here, so take with a
| grain of salt.
| dasudasu wrote:
| Then you can hijack the noise canceling device and obtain
| the original signal. Also the canceling effect is likely
| never perfect, so there would still remain part of it
| going through.
| [deleted]
| matham wrote:
| What if you use one random source to contentiously change
| the white noise parameters (mean, std).
|
| E.g. use something like a illuminated disco ball that
| continuously randomly changes the source light angle and
| intensity.
| kerkeslager wrote:
| I think it would be very difficult to escape from
| diffusion problems.
| kanobo wrote:
| I'm going to put on my pop-science-fiction hat on and revise
| the Privacy Bulb to include a geiger-muller vibrating tube
| and a dollop of uranium for random vibrations. I was a fan of
| spy vs. spy as a child and I am full of bad ideas right now.
| hinkley wrote:
| We've known each other, for so long...
| SilasX wrote:
| Since you mention it, I got to thinking about whether we can
| have a microphone equivalent to the physical covers for webcams
| -- that is, a physical means that ensures the device can't
| detect anything usable, even if an attacker was able to turn it
| on without you knowing.
|
| Something like, a vibrating module that you don't really notice
| but which clouds out any sounds the microphone would pick up
| (or, to go your route, injects fake audio). You turn it on when
| you want to be sure the microphone isn't listening, just like
| you can cover the webcam.
| plutonic wrote:
| You mean something like this [0]? You could use this to trick
| your computer/phone into using the audio jack for its
| microphone, but since the mic-lock passes no usable signal,
| you'll be better protected. It doesn't otherwise incapacitate
| the internal microphone, though.
|
| [0] https://www.amazon.com/Mic-Lock-Microphone-Blocker-Pack-
| Surv...
| SilasX wrote:
| It would need to block the microphone itself that picks up
| ambient noise -- I don't think there's anything on e.g. a
| MacBook Air that you could plug that into and block sound.
| kanobo wrote:
| Some offices employ white noise privacy machines, you can
| find them on amazon. And the Japanese have the Sound Princess
| for flush noise privacy at the toilet. I have yet to find a
| product where you don't notice that it's on though, would be
| a great invention if possible.
| spockz wrote:
| Or you could turn on the shower and faucets in the bathroom
| and talk there. Or does that only work in the movies?
| briandear wrote:
| It does work, but you can have filters that can remove that
| noise electronically enough to get some actual voice
| signal. Faucets along with whispering directly in the ear
| would work. But a better choice is to simply write on a
| piece of paper instead of talking.
| [deleted]
| feralimal wrote:
| Sorry - but that sounds like BS. Think about it - a hanging light
| bulb vibrates when you speak... Really? I don't see any movement,
| and I'm right there.
|
| But yet, that can be picked up 25m away by a telescope? With
| equipment that costs less than $1000? No way.
|
| Sounds like some phony story to me, that's meant to make us think
| spies have superpowers, or even that we're all being spied on.
| (Which we are, but not like this.)
| jamesgeck0 wrote:
| > Think about it - a hanging light bulb vibrates when you
| speak... Really? I don't see any movement, and I'm right there.
|
| I don't see any movement on my computer speakers or mic when
| they're emitting or receiving sound, but they wouldn't function
| if vibration wasn't happening. You can measure the vibrations
| from a short distance away with a laser setup that costs about
| $300 IIRC.
|
| So the basic concept is sound. After that it's just a question
| of what kind of measurement setup a government agency with
| absurd amounts of time and money could cook up.
| meritganset wrote:
| I can't tell if this is serious or not. You realize that not
| all vibrations are visible by eye, right? In fact, the vast
| majority aren't.
| feralimal wrote:
| Do you really think a telescope can pick up the reflected
| vibrations from a lightbulb, using a telescope 25m away?
| bbbobbb wrote:
| Here similar experiment, 6 years ago:
| https://www.youtube.com/watch?v=FKXOucXB4a8
|
| If you think that actual government agency cannot do even
| more easily with better equipment in 2020 you're kidding
| yourself.
| feralimal wrote:
| I watched the video. I'm sorry, but its inane. This is
| the worst sort of science magic. In fact its just
| trickery.
|
| Do you seriously think that you have been provided
| evidence in that video? All that happened is that I ended
| up looking at a leaf and packets of things that weren't
| moving at all. That's not evidence!
|
| It says that they are picking up vibrations from a leaf
| or bag of crisps. But they don't show you those
| vibrations. They just give you a bunch of graphics and
| fuzzy sounds and tell you that they have done something.
|
| You do see that this is could be very simple video
| trickery right? As with the initial article - there's a
| claim, but nothing to really be able to use to verify
| that claim. Just a graphic, and references to Shazam.
| Perhaps this is guerrilla marketing for Shazam? Its a
| more viable thesis anyway, given the evidence!
| thebean11 wrote:
| You should discredit the Wired article
| feralimal wrote:
| Well, ok.
|
| Firstly, note that it provides no evidence. It has a
| claim, and shows a fancy graphic. That's it. Its not
| evidence. Anyone can make that sort of thing up. How can
| one differentiate this from a story I just made up?
|
| Digging in, it says: "LED bulbs also offer a signal-to-
| noise ratio that's about 6.3 times that of an
| incandescent bulb and 70 times a fluorescent one."
|
| Why? Why are LEDs better for this noise reflection stuff,
| than incandescent or fluorescent ones? They're all in
| glass. The heat of the glass is stable. The LED itself
| surely can't help.
|
| Why does Shazam feature in these tests, at all?!
|
| It also says: "Researchers have known for years that a
| laser bounced off a target's window can allow spies to
| pick up the sounds inside. Another group of researchers
| showed in 2014 that the gyroscope of a compromised
| smartphone can pick up sounds even if the malware can't
| access its microphone."
|
| Right. Are we meant to believe that this is what spies
| do? I mean, a spy just has to access whatever systems are
| already at his or her disposal and listen to your calls.
| They don't need to do any of that!
|
| And: "Still, Nassi says the researchers are publishing
| their findings not to enable spies or law enforcement,
| but to make clear to those on both sides of surveillance
| what's possible. "We want to raise the awareness of this
| kind of attack vector," he says. "We're not in the game
| of providing tools.""
|
| So, they even say that this article is about raising
| awareness of this kind of attack vector. They are raising
| awareness. Thanks spies!
|
| The article is a joke. At best this is a puff piece for a
| spy agency, or more likely just to increase paranoid
| awareness amongst those in tech. Be scared, danger
| everywhere! There are spy agencies listening to you
| everywhere - they're not using your phone, they use light
| bulbs and leaves!!
| x2f10 wrote:
| The video is a simple demonstration. If you want more
| details, there's an accompanying website and white paper
| published by MIT [1].
|
| 1. http://people.csail.mit.edu/mrub/VisualMic/
| feralimal wrote:
| PS, at what point would alarm bells ring for you, re this
| story. If they had said that they could pick up voices
| from a lightbulb with a telescope that was 50m away?
| 100m? 1000m?!?
|
| I suspect that alarm bells wouldn't ring at all....
| feralimal wrote:
| And why should some skepticism of an article relating to the
| purported tools of spycraft be downvoted? Its ok to expect more
| than a simple schematic, surely?
| deadmetheny wrote:
| It's because you're point-blank wrong and keep doubling down
| on it instead of taking the L.
| Dahoon wrote:
| Of course it is Israeli..
| fortran77 wrote:
| @dang -- this seems like an unproductive comment.
| partiallypro wrote:
| I'm not sure on the cost, but I know it's common to use lasers at
| an angle on windows to spy on conversations via a laser
| microphone. That requires less of a line of sight. Is this a
| cheaper method?
| ravenstine wrote:
| One way you can do this without another light source is to bounce
| a laser beam off a window or other things that are reflective.
|
| In fact, the same principle can be achieved with radio. The
| Russians once planted a device in a wooden seal they gave to a US
| ambassador as a gift which, when a focused radio beam was aimed
| at it, would reflect and oscillate that beam due to vibrations in
| the air.
|
| https://en.wikipedia.org/wiki/The_Thing_%28listening_device%...
| perch56 wrote:
| Leon Theremin was a genius that also created one of the first
| electronic instruments carrying his name now.
|
| https://en.wikipedia.org/wiki/Theremin
| mhh__ wrote:
| In any building spies had access to there was a game of cat and
| mouse as (for example) spies would see people with radio
| equipment scouring rooms through the window as they heard their
| bugs go pop one by one.
|
| Peter Wright (who wrote spycatcher) was the one who first got
| to look at The Thing; He actually broke it and had to make a
| new membrane for the microphone. He also invented (within MI5
| at least) their technique for detecting superhet receivers
| (RAFTER), at one point they apparently were parked next to the
| soviet receiver.
| russellbeattie wrote:
| I remember in the 1990s I was doing contracting work in SoCal
| and got a job at one of the big defense contractors near LAX.
| (Trying to remember which one... Hughes?) I lasted only one
| week as the building was totally secure - no windows at all.
| Life is waaaaaay to short to work in a hole like that.
|
| Maybe someone with more info can fill in the details, but if I
| remember correctly, when Nokia changed their Silicon Valley
| offices to downtown Sunnyvale almost a decade ago, they were
| worried because Apple had offices in the adjacent building. If
| I remember correctly Nokia put in a bunch of security glass to
| prevent spying from vibrations in the windows. (There's some
| irony there, I know...)
| panda88888 wrote:
| Yup. It's fairly standard. For classified work the rooms and
| entry/exit protocols have to meet certain security
| requirements based on the classification level. No windows
| and no electronics are standard. No walls that is exposed to
| the exterior. I've been in room within a room setup when it
| was warranted.
| acidburnNSA wrote:
| Back in the 90's I found an old cardboard box full of
| radioshack electronics components and a paper schematic of how
| to put it together. I asked my dad what it was. He had been
| into an electronics hobby in the 1980s and told me that it was
| a amplifier to receiving laser light bounced off of a window
| for spy stuff. I couldn't believe it. The kit became my first
| significant soldering project. I got it all together and put my
| beloved laser pointer on a tripod and tried bouncing it in. I
| never did get it to the point that I could hear voices but boy
| could I ever hear cool vibration noises when I tapped the
| window.
|
| It was extremely fun and I've been soldering things here and
| there ever since.
| balls187 wrote:
| Most of my office windows at Boeing had little ultrasonic
| buzzers on them to prevent such an attack.
|
| On my offices was actually in a large farad cage to
| reduce/eliminate EMF leaks from workstations.
| SEJeff wrote:
| I take it you work on some "government" projects? I wonder if
| that is all TEMPEST grade shielding.
| akamia wrote:
| When I worked at Boeing, we even had them on the windows of
| offices that weren't being used for government projects.
| The company's commercial business was also a target for
| spying so they were very protective in general.
|
| To this day, the company's laptops don't have cameras and
| they have a whole process that you have to go through to
| use a camera anywhere on company property.
| balls187 wrote:
| Yeah, used to work for Boeing's defense groups.
| acidburnNSA wrote:
| Wow. That's super interesting. So it was considered a
| credible threat.
|
| Huh you can actually buy such things on Amazon.
|
| https://www.amazon.com/Shomer-Tec-SHLSD-Laser-
| Surveillance-D...
|
| Edit: yikes, those reviews...
| spitfire wrote:
| Woah. Check out the recommendations on that page. There's
| some great stuff in there.
| ravenstine wrote:
| It's basically a 555 timer, some resisters, and a piezo
| buzzer. Hardly worth 50 bucks! You can build one yourself
| for a mere fraction of that.
| freehunter wrote:
| For a big business like Boeing, buying one at $50 would
| be far more palatable than building one from parts.
| ravenstine wrote:
| Dang, you're right! _This is a business I need to get
| into._
| zszugyi wrote:
| I'm sure getting vetted to be a vendor for DoD/Government
| projects is super easy.
| jascii wrote:
| Ultrasonic buzzers? I kinda fail to see how that would help,
| shouldn't be too hard to filter out the ultrasonic range
| noise.
| Zenst wrote:
| Basically drowns out the room vibrations upon the window as
| it is a in direct contact. You can make your own with piezo
| discs and small circuit to drive them. That and high
| frequency will not cause added noise noticeable to humans.
| noir_lord wrote:
| Not if it's random.
|
| It's the vibrations from sound on glass they want and those
| are tiny by comparison to the input.
| GhostVII wrote:
| Important caveat:
|
| _The voice and music recordings they used in their
| demonstrations were also louder than the average human
| conversation, with speakers turned to their maximum volume_
|
| I can clearly see vibrations in glass near loud speakers with my
| naked eye, but when someone is speaking I generally can't see any
| vibrations. Still really cool that they were able to reproduce
| sounds this way, but it's not like you can spend 1k and be able
| to actually listen to conversations using this method.
| lostmyoldone wrote:
| If their chart is correct, the 30cm mirror show a 20db
| improvement in SNR at 200Hz compared to 20cm, same curve but
| 20db lower gain.
|
| That is an absolute crazy scaling, I'm not entirely sure how
| that's possible, though I have a suspicion. If it's an actual
| scaling law that can be exploited, I would expect you can
| extend this to entirely practical audio volumes on a shoestring
| budget.
| Puts wrote:
| Apparently this is 1947-tech:
| https://en.wikipedia.org/wiki/Laser_microphone
|
| I even remember there where schematics for a laser-microphone
| circulating on the early 2000s internet that could translate the
| vibrations of windows into sound.
| OkayPhysicist wrote:
| I built one of those in college. Hardware's super simple, but
| actually getting it alligned is a total PITA.
| mdturnerphys wrote:
| Previous discussion of source:
| https://news.ycombinator.com/item?id=23498185
| wallacrw wrote:
| I've always wondered -- if I used this on the board room window
| to listen into public company earnings meetings, is that inside
| information? Technically, the information is "public" in that
| anyone could do what I'm doing...
| pmoriarty wrote:
| Along similar lines, I've wondered about how often restaurant
| and bar owners have bugged their own premises.
|
| There's probably a lot of valuable information discussed in
| such establishments.. especially, say, around Wall St.
|
| Regarding the legal aspects, I'm not sure how much of a legal
| expectation of privacy one has in a "public" place such as a
| restaurant or bar, and we've pretty much already accepted
| ubiquitous video surveillance in such places (even if such
| videos are often without sound).
|
| Someone could potentially infer speech just by lipreading
| soundless videos, but if someone did decide to use audio
| surveillance on their own property in a bar, restaurant, or
| other place of business, is there any law against that?
|
| Quite apart from the legal and ethical objections that might
| arise against doing this, I'm sure some business owners are not
| above giving in to the temptation to spy on their patrons,
| especially if there's a big profit motive (like getting access
| to inside information by spying on Wall St execs gossiping over
| drinks or dinner).
|
| That's not to mention dirt that might be revealed in
| conversations considered to be "private", which could be used
| to blackmail people or for other nefarious purposes.
|
| The technology to perform such spying has been around for a
| long time, and in a bar or restaurant the owner (or rogue
| employee, or customer even) wouldn't have to resort to exotic
| techniques such as this light bulb trick. A simple microphone
| would suffice.
| jeffdubin wrote:
| Some Dunkin Donuts stores in the New England area were
| (decades ago) accused of listening to their customers by
| having microphones at seats where customers ate. Not sure if
| that was intentional or part of their security system as they
| claimed. [0]
|
| [0] https://apnews.com/d7e29ace8f0cfdd8e4377e70ef26eff8
| briandear wrote:
| > Along similar lines, I've wondered about how often
| restaurant and bar owners have bugged their own premises.
|
| In a few select Houston strip clubs.. all the time, or at
| least ten years ago some did, the ones owned by certain
| organizations. I haven't been around that scene for a decade,
| so I can't speak to now. I know of a few other places that
| seemed to magically never have trouble with city officials or
| permitting. Another such place, an after hours club, was
| frequented by the mayor's "party-oriented" daughter, never
| had trouble with police raids, or fire marshals. The venue
| survived unscathed until the next mayor took over and such
| leverage became unavailable. The Texas Alcoholic Beverage
| Commission was the only real challenge, but often the local
| cops would be knowledgeable about pending raids and would
| graciously provide some advance notice. It certainly helped
| that many of those cops were paid as off duty private
| security by the venue. DEA was another frequent adversary,
| but those folks aren't as undercover as they thought they
| were. I might suggest that the DEA was (or maybe still is,)
| one of the more sketchy law enforcement agencies in the
| government.
|
| Just under the surface of "normal," there is some really
| fascinating stuff that goes on.
| ColanR wrote:
| I'm sure that one way or the other, that question has been
| dealt with exhaustively. My guess, the information you obtain
| is considered definitely not public, even though it's possible
| for a member of the public to obtain.
| oh_sigh wrote:
| Yes - Economic Espionage Act of 1996
|
| It is not public because there is a reasonable expectation of
| privacy.
| pier25 wrote:
| This is only for incandescent lightbulbs, right?
| Romanulus wrote:
| All cool tech aside, I'll be sure to update the single light-bulb
| hanging from a thread in my interrogation room now.
| irontinkerer wrote:
| I was expecting to be dissapointed (I thought this was going to
| be a test in the same room, with perfectly calibrated equipment)
| but I was wrong. Very impressive that you can do this at that
| distance and with affordable ($400) equipment. I wonder how long
| intelligence agencies have been using this capability.
| hinkley wrote:
| I knew someone who started building one of the laser based
| units in the fall of 1990, in high school. So that's 17 or 18?
|
| By the end of the decade or beginning of the next, we had
| telecom hardware companies filtering the signal to the activity
| LED so that you couldn't read packet info out of the
| flickering.
|
| Odds are good that someone combined those ideas a lot earlier
| than we might like to think.
| helios_invictus wrote:
| I believe since the 80's
| draw_down wrote:
| To defeat this, don't you just do what the mobsters in movies do?
| Play music or make some other loud noise and then whisper or talk
| softly close to each other?
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