Please create an account to participate in the Slashdot moderation system

 


Forgot your password?
Close
typodupeerror
×
Privacy Science

Snooping Through Walls with Microwaves 217

Posted by ScuttleMonkey from the time-to-buy-stock-in-tinfoil dept.
denis-The-menace writes "According to an article from newscientist, scientists have devised a system to use microwave energy for surveillance. If people are speaking inside the room, any flimsy surface, such as clothing, will be vibrating. This modulates the radio beam reflected from the surface. Although the radio reflection that passes back through the wall is extremely faint, the kind of electronic extraction and signal cleaning tricks used by NASA to decode signals in space can be used to extract speech. Although, I doubt it would work in this room"
This discussion has been archived. No new comments can be posted.

Snooping Through Walls with Microwaves More

Snooping Through Walls with Microwaves

Comments Filter:

  • 1st sign the feds are onto you... (Score:5, Funny)

    by titla1k ( 875330 ) on Wednesday October 26, 2005 @06:29AM (#13879241)
    is there's a van sitting outside your house, with a whole lot of kitchen appliances pointing at it.
    • ...owned by the company

      Flowers
      By
      Irene
    • Or a "Flowers By Irene" van...

    • Re:1st sign the feds are onto you... (Score:5, Funny)

      by moviepig.com ( 745183 ) on Wednesday October 26, 2005 @07:45AM (#13879452)
      If people are speaking [then] clothing... will be vibrating.

      So the hell with eyes... it's actually possible to undress her with your diction...

    • OLD NEWS:This has been in active use since the 50s (Score:5, Interesting)

      by goombah99 ( 560566 ) on Wednesday October 26, 2005 @10:57AM (#13880538)
      The first sign the Fed's are listening to you is when they give you a nice small bust of lenin for your mantle peice. That's exactly what the British did to the russian ambassador back in the post world-war two era. They gave him a a gift of a small statue and inside it they had mounted a corner cube which is a passive device that enhances the retro-reflection of microwaves beamed at it. (read about it is Peter Wright's (banned in UK) book Spycatcher--wright [amazon.com] was the science officer for MI5 and inventor of the technique [bbc.co.uk])

      The second sign is when you feel toasty warm and the chair feels cold. In the 70's and 80's the carter and reagan administrations were perpetually complaining that the level of microwave energy measured inside the US embassy exceeded the OSHA limits for exposure. Eventually the US built a new embassy with enhanced shielding. UNfortunately the Soviet's put listening devices into the bricks. The embassy had to be knocked down and rebuilt. Of course, peter wright [bbc.co.uk] did exactly the same thing to the Soviet embassy in canada. Each night he snuck into the construction site and pulled wires up the inside of the walls to his microphones in specially made window sills. The soviet's learned about it from a mole in MI5 and had to build a second interior wall so that no rooms were near the windows.

      Doppler microwave spying is quite old. As is laser vibrometry on windows.

      • Used Here (Score:4, Interesting)

        by waldoj ( 8229 ) <waldo@@@jaquith...org> on Wednesday October 26, 2005 @02:25PM (#13882844) Homepage Journal
        Here in Charlottesville, home of the National Ground Intelligence Center (you might know them for a little kerfuffle involving their providing bad intelligence about nuclear weapons to some president...something about a war?), they've long had a thick wire mesh covering all of their windows. A former employee told me, when I was a kid, that it was designed to reflect microwaves for this very reason.

        -Waldo Jaquith

      • Re:OLD NEWS:This has been in active use since the (Score:4, Interesting)

        by Ungrounded Lightning ( 62228 ) on Wednesday October 26, 2005 @05:52PM (#13884531) Journal
        This stuff has been happening since the fifties. Nothing new here.

        The russians did that to the US, too. With a nice giant carving of the Great Seal - with a device behind a small hole beneath the beak.

        Consisted of a cavity resonator about the size of a stack of 10 or so dimes, with a tuning post up the middle, a diaphragm for one end (to detune it according to air pressure) and a wire antenna maybe a foot long coupled into the cavity. Excite it with a microwave signal near but not dead-on the resonance and the reflection is amplitude modulated by the sound from the room.

        Better yet: Put a diode in a movable surface. Excite it and it returns harmonics (easy to sort out from other reflections because they're on a different frequency), phase-modulated by doppler shift from the object's motion (like its variant FM, PM is very noise-resistant).

        Russian laborers constructed an embassy where the walls were FULL of thousands of diodes - embedded in the construction material. US had to abandon the building and build one of their own. News items suggested the diodes were to make it hard to sniff for bugs. But IMHO they were the bugs themselves, using the harmonic-generation/doppler/PM trick.

        Like the posting in the root article, this makes every surface a bug. You have to get diodes into them, but the return is cleaner and stronger than echoes from a passive reflector.
    • Is it getting warm in here?

  • Invest in AA (Score:5, Funny)

    by TripMaster Monkey ( 862126 ) * on Wednesday October 26, 2005 @06:29AM (#13879242)

    I think I'm going to buy stock in Alcoa Operations [alcoa.com]...with shenanigans like this going on, they can only increase in value.

    In the meantime, here's some telltale signs you might be under microwave surveillance:
    • You feel slightly warmer than is normal.
    • Your food seems to be cooking itself.
    • Metal objects in your house give off sparks for no good reason.
    • Your coffee remins hot for a very long time.
    • Your beer remains cold for a very short time.
    • All your CDs are covered with tiny cracks and will no longer play.
    • Your house pets smell delicious.

    Watch for these signs and protect your privacy...cause the government certainly isn't going to.

    • Re:Invest in AA (Score:4, Informative)

      by Anonymous Coward on Wednesday October 26, 2005 @06:37AM (#13879263)
      Aside from the fact that farmers and subsidies have all but shut down Alcoa in the US, Aluminum is a poor choice, and hence wouldn't be used. Lead. That would be the metal of choice. It has properties which make it excellent at sound proofing. Vibrating aluminum would modulate their signal quite nicely.

    • Re:Invest in AA (Score:3, Interesting)

      by MacGod ( 320762 )
      On the plus side, it should automagically explode all the super-evil RFID tracking tags in your razors and potato chip bags and whatnot. It's nice to trade one form of surveillance for another, and this sure would be faster than putting each individual item in the microwave oven one at a time!
      • About your sig:
        "Reality is merely an illusion, albeit a very persistent one " -Albert Einstein

        I strongly doubt Einstein ever said that. After all, he was a die-hard realist, which was also the reason why he had big problems with the interpretation of quantum mechanics.
        • Google it and there's lots of site who're convinced he did. Granted that some of the origins seem to stem from an unsubstantiated chain mail, but he did seem to come up with all sorts of soundbyte gems.

          Here [quotationspage.com] is one such site.

        • That's because his quote was intended to convey: "Time is merely an illusion, albeit a persistent one."

          To put this into perspective, through relativity he found that "time" does not flow as was so often thought in the past. Rather it is a rather static entity that is described by a higher dimension that we cannot percieve directly. Since we cannot percieve the fourth dimension directly, we instead perceive snapshots of it on a three dimensional plane, thus producing the "illusion" of time.

          Of course, Quantum

    • Re:Invest in AA (Score:2, Insightful)

      by mikiN ( 75494 )
      In the meantime, here's some telltale signs you might be under microwave surveillance:

      Add to this
      • Your WiFi connection becomes erratic, to the point of being unusable

  • Just Friggin' Great (Score:4, Funny)

    by SecureTheNet ( 915798 ) on Wednesday October 26, 2005 @06:29AM (#13879243) Homepage
    Now, when the NSA spies on me, my wi-fi network will be unable to work due to interference!
    • Maybe the NSA will just use the waves your WLAN sends out anyway. Which has the advantage (to the NSA) that there's no additional wave source which you might be able to detect.

  • oh no (Score:5, Funny)

    by NoGuffCheck ( 746638 ) on Wednesday October 26, 2005 @06:30AM (#13879247)
    luckily my parents basement has thick walls.

  • Makes little difference (Score:5, Interesting)

    by polysylabic psudonym ( 820466 ) on Wednesday October 26, 2005 @06:34AM (#13879259) Journal
    How many criminals protect against laser audio surveillance, where a laser beam is bounced off a window or other rigid surface, and the sound from the room vibrates the surface, wobbling the beam, the wobble being translated into audio by the snooper.

    The laser can be defeated by double glazing (I think), devices to vibrate windows and laser detectors (to tell you if you're being listened to).

    A microwave device can be defeated by the good old tinfoil hat - by which I mean wallpapering in foil or otherwise turning the room into a faraday cage.

  • In analogue phone days (Score:3, Interesting)

    by DrSkwid ( 118965 ) on Wednesday October 26, 2005 @06:38AM (#13879265) Journal
    Some associates were spied on by the telephone.

    Just because the receiver was on the cradle didn't mean that the microphone wasn't active.

    The cops played stuff back in interviews/court that was off topic but was the occupants bitching about each other to try and divide and conquer them.

    This was in Leeds, UK.

    I can't remember many more details or find a link. I didn't know them at the time and only heard about it later as a warning.

    • I didn't think that sort of evidence was admissible in a UK court.

    • Re:In analogue phone days (Score:5, Interesting)

      by Richard_at_work ( 517087 ) on Wednesday October 26, 2005 @07:44AM (#13879448)
      MI5 developed this in the 1950s, and called it Special Facilities. All it required at the start was a modification to the phone - a single washer, and the phone could be used as a surveillence device. Later versions enabled activation using high frequency radio waves to activate the telephones microphone and required no modification to the phone itself.

      Survellience was also carried out against embassy cypher machines using unshielded telephone cables picking up eletromagnetic emissions from the cypher machines, in many cases enabling the reading of both the en clair message and the cypher material.

      None of this was admissable in a UK court. Phone tap evidence still isnt.
    • It used to be that the old dot matrix printers used to require heavy shielding, because the solenoids inside the printer head would generate a certain radio "sound" for each letter. A van could sit outside an embassy, focus in on the location of a printer, and reproduce a duplicate.

      The United States used this against the soviets for quite a while.

  • Not new tech (Score:4, Informative)

    by Anonymous Coward on Wednesday October 26, 2005 @06:39AM (#13879267)
    I don't think this a new technology. I think that this is just a new take on a technology that Léon Theremin (inventor of the Theremin instrument) was working on for the KGB in the 50-60s. He was using infrared bounced off of windows to detect conversations inside (or something). http://en.wikipedia.org/wiki/L [wikipedia.org]éon_Theremin
    • Unfortunetely, he never did get all the bugs out of his device. People always knew they were being listened to when the creepy music started. "Quiet, it's the KGB .. or the Krell."
    • Interesting. My dad was a psychologist and in the '70s he had a grant to study the effects of microwaves on human behavior. He said that at the time, the Russians were beaming microwaves at the US embassy there, but he (and apparently the American government) didn't know what they were trying to do. They just ended up deflecting it with tinfoil or something (maybe tinfoil hats aren't so crazy!).

      Maybe your story explains it.

  • Fluff piece (Score:5, Informative)

    by gtoomey ( 528943 ) on Wednesday October 26, 2005 @06:42AM (#13879277)
    This "story" is just a reference to a patent application [uspto.gov].

    Even at 100GHz, the wavelength of microwaves is 3 mm. But sound waves inside a room would cause a surface to vibrate perhaps 0.001 mm. You cant modulate a 3mm wave to record 0.001 mm changes.

    • Doh!! I'm am amateur radio operator. I should have been able to do the math too.

      Yes. The last time I heard this story, I thought they were using a laser beam -- which makes a lot more sense.

    • Re:Fluff piece (Score:5, Interesting)

      by Ancient_Hacker ( 751168 ) on Wednesday October 26, 2005 @07:50AM (#13879462)
      >"You cant modulate a 3mm wave to record 0.001 mm changes." You're partially correct. It would be difficult to detect the modulations, EXCEPT that if you're also the sender of the original signal, you can mix the incoming and outgoing signals and extract the phase difference. Subtraction is a VERY powerful signal-extraction method!

      There's an anecdote in the engineering field: where some poor sods at Racal-Dana had a phase detector at 50MHz that was so sensitive to vibration they had to stop their experiments whenever a plane took off from Orange County Airport (quite a few miles away). They eventually had to get special thick aluminum wall castings to enclose the phase detector to block the vibrations. And this was at just 50MHz. Phase detectors get more sensitive proportional to operating frequency, so a 5,000 MHz phase detector is *mighty* sensitive!

      • Another important part is the signal processing software.

        SETI has developed some *damn* impressive software in their search for a signal at intersteller distances. I remember one talk I went to 6 or 7 years ago. The woman was describing the setup, and said that they used (I think it was) one of the Pioneer crafts as a basic check to make sure the software was turned on and working. This thing is a 4 watt source out past Jupiter - that's a christmas tree light halfway across the solar system. The signal
    • Water is used as reflector for dipol antennas at sea (you only need the upper half of the antenna).
      Wouldn't that mean that you should be able to see humans (made of 80% water) inside buildings by using radar/microwave technology. If that was possible, perhaps you could use lip reading, to see what people are saying. Lips ar much bigger than 3mm.

    • Re:Fluff piece (Score:5, Insightful)

      by pz ( 113803 ) on Wednesday October 26, 2005 @08:53AM (#13879762) Journal
      Even at 100GHz, the wavelength of microwaves is 3 mm. But sound waves inside a room would cause a surface to vibrate perhaps 0.001 mm. You cant modulate a 3mm wave to record 0.001 mm changes.

      Interference detectors, more commonly known as interferometers, can detect distances far below the wavelength used to make the measurements. For example, 800 nm infrared laser light can readily be used to resolve 5 nm differences (I've worked on the development of such a system). Further, the distances being considered for measuring the movement of things like clothing or the throat and chest of the speaker are far above one micron (0.001 mm): put your finger on your throat and speak; think that's one micron you're feeling?

  • It was news... 45 years ago. (Score:4, Insightful)

    by Ancient_Hacker ( 751168 ) on Wednesday October 26, 2005 @06:42AM (#13879278)
    The Soviet KGB have been doing exactly this since before 1960. Windowpanes make good microwave reflectors. All it takes is a simple microwave source and mixer. Nothing new to see here.
    • That was lasers. Microwaves pass straight through glass.

      • Re:It was news... 45 years ago. (Score:5, Interesting)

        by Ancient_Hacker ( 751168 ) on Wednesday October 26, 2005 @07:30AM (#13879410)
        Uh, not quite. For many reasons.
        • There were no "lasers" in 1960. At least not the very stable continuous-wave lasers that you need for this, and especially not in the USSR.
        • Think-- do lasers go through glass? Do lasers bounce off glass? Might other wavelengths of electromagnetic radiation act similarly?
        • Microwaves bounce off most anything, if you pick the right angle. Conveniently, most buildings have the windows recessed a bit, and any concave corner makes an EXCELLENT "corner reflector", which has the amazing property of bouncing any incident beam right back to the sender.
        Not only did they bounce microwaves off glass-- they had the hutzpah to give the US ambassador a honorary plaque, which he hung on his office wall. Unbeknownst to us, there was a little diaphragm inside the plaque, just the right wavelength to reflect K-band microwavesm, which vibrated very nicely to every word spoken in his office. Look it up.
        • It's not so much the angle, as the polarization. At bruster's angle (around 36 degrees for glass) light polarised in a certain way will all bounce off. Light polarised in the opposite way will all pass through.
          • Methinks you're looking at it kinda backwards. Without the correct angle of incidence, you get neither reflection nor polarization. At the correct angle, you get reflection, which just so happens to also be polarized. But the incident polarization cannot *trigger* reflection, no mather what the angle of polarization. Regards!
        • He-Ne (continuous) lasers were demonstrated in 1960. If Bell Labs could do it, I would expect that Russians could do it. Lev Landau could do almost anything with 1/2 the number of steps of anyone else :-)

          The corner cube idea is brilliant, so thanks for the post. I'm starting to understand why the test of a truely excellent machinist is to make a nearly perfect cube. It means they can work for the spooks making 'innocent' items to the precision needed to turn frames into corner cube reflectors with one

          • Sarcasm is better when it fits the situation. There are scads of radar images showing very strong reflections from windowsill corners. This is not an arguable phenomenon. In fact the USAF spent many $$$ trying to figure out how to minimize getting these reflections-- they tend to be much stronger than the reflections from more desireable landmarks.

            No great precision is needed, as the surfaces only need be as flat as 1/4 of the wavelength-- several centimeters. And with the transmitters right across

        • Not only did they bounce microwaves off glass-- they had the hutzpah to give the US ambassador a honorary plaque, which he hung on his office wall. Unbeknownst to us, there was a little diaphragm inside the plaque, just the right wavelength to reflect K-band microwavesm, which vibrated very nicely to every word spoken in his office. Look it up.

          I looked it up. 330 MHZ is not K-Band microwaves. It's UHF. HF is from 3-30Mhz VHF is from 30-300...

          The bugged seal had a resonant quarterwave antenna tuned to 330
          • >K band is near 20 GHZ. There wasn't much in the 1 GHZ and up band then. Vacuum tubes just didn't work that high.

            You seem to be confusing the years or the technology. By 1960 there were K-band magnetrons and klystrons capable of kilowatts of CW output power.

            And yes, the seal might have been at VHF or UHF frequencies, but that just strengthens my argument-- this is REALLY old news-- It could have been done as early as WW2 !! Regards, A_H

        • It took me a few tries, but I found this [nyud.net] excellent site which discusses the plaque story and has lots of links that look quite interesting as well.
          • Good info, but beware of anything from "Spycatcher". Quite a bit of the info in there is uncorroberated and even plainly incorrect. He writes that he discovered local oscillator emanations in 1960-something and the CIA wasnt aware of it.

            Not so, radio receivers as far back as 1938 were SPECIFICALLY designed with extra care, isolation, and shielding to prevent local oscillator emanations. Navy subs even went to the length of using obsolete but local-oscillator-less TRF radios, just to avoid the slightes

    • I agree, seems like a TEMPEST in a teapot to me.

  • How long? (Score:3, Funny)

    by xor.pt ( 882444 ) on Wednesday October 26, 2005 @06:44AM (#13879286)
    How long till they incorporate this feature into an iPod?

  • Food fun (Score:4, Funny)

    by Snamh Da Ean ( 916391 ) on Wednesday October 26, 2005 @06:44AM (#13879287)
    Man, I knew that burrito I put in the microwave last night when I came home from a party was speaking to me...

  • This isnt new (Score:3, Interesting)

    by MrEcho.net ( 632313 ) * on Wednesday October 26, 2005 @06:46AM (#13879290)
    This tech has been around for a very long time, just not in the public sector.

    If you look at any high security building(NSA, etc) they will have multi layers on the outside and inside of the buildings.

    Not only is it physical security, but sound and wireless security.
    • They're called SCIFs (Sensitive Compartmented Information Facility), more info at: en.wikipedia.org/wiki/Scif [wikipedia.org]

      Also see TEMPEST - "a U.S. government code word for a set of standards for limiting electric or electromagnetic radiation emanations from electronic equipment such as microchips, monitors, or printers. It is a counter-intelligence measure aimed at the prevention of electronic espionage. The term TEMPEST is often used more broadly for the entire field of compromising emanations or Emissions Securi

  • foil vibrates too (Score:2, Insightful)

    by dwater ( 72834 )
    Wouldn't the sound in the room vibrate the foil on the wall? Said foil would reflect microwaves very nicely, I suspect...
    • You're right. The foil will have to be glued to the wall sheeting, egg cartons to the foil, another layer of foil over the egg cartons.

      Let 'em try then!
      • If you'll allow me to adapt a popular urban legend for this particular scenario...

        American scientists spent millions of dollars on producing wall surface coverings that would absorb any voice vibrations in order to counter microwave listening devices.

        Russian scientists used a pencil.
  • My preference to microwaves transmitted in order to invade my privacy is to send hot lead back,at high speed

  • Very dangerous!!! (Score:4, Informative)

    by elgatozorbas ( 783538 ) on Wednesday October 26, 2005 @07:13AM (#13879359)
    The summary mentioned microwave ovens, so some may be tempted to play around with a DIY radar. Don't!!! Of all domectic appliances a microwave is about the most dangerous to take apart. The RF radiation has a very high power and is invisible. When exposed to the electromagnetic field, currents start to flow inside the human body (mostly close to the skin) giving rise to burn-like wounds. Especially the risk of eye injury is significant. Don't try this at home.

  • I can see the RIAA using it!! (Score:3, Funny)

    by AnonymousYellowBelly ( 913452 ) on Wednesday October 26, 2005 @07:14AM (#13879360)
    Yeah, they listen to the music playing inside your house. Say you are hearing the latest hit from Britney Spears but the RIAA has no record of you buying it, well they turn the 'volume' to 11 on their microwave emitter and fry your balls, burn your house and kill your dog. Justice has been served, right?

  • Tinfoil hats (Score:3, Insightful)

    by Jerom ( 96338 ) on Wednesday October 26, 2005 @07:17AM (#13879368)
    Funny thing is, with this kind of device tinfoil hats will actually improve "the black suits" reception, since tinfoil easily vibrates and reflects radiowaves really well.

    *Sigh* what now?

    J.

  • Foil Room fallacy (Score:3, Informative)

    by obfuscated ( 258084 ) on Wednesday October 26, 2005 @07:42AM (#13879442) Homepage
    The "Foil Room" won't help against snooping as you'd like to believe. (Prepare to ditch all your foil hats!!).

    To truly block signals, you'd need to build a actual Faraday "cage" built with the smallest possible 'holes' so the waves created inside (be it voice, the sound of you typing or even waves emitted by the blinking LED from your Ethernet card) will be cancelled out. This is the same technology that the intelligence agencies employ against counter intelligence. That with foil (which is properly grounded) will work.

    Solid surfaces such as foil can actually act as large AMPLIFIERS if implemented incorrectly since the waves will

    Note that your microwave is surrounded by a Faraday cage to protect you from the rays; not foil.

    A quick Google to back up my post yielded this page [montalk.net] discussing similar topics.
    • I'm not convinced. Satellite dishes and the lining in your microwave have a bunch of little holes in them as a matter of convenience. Having the holes allows:

      1. To see through the material (to see inside a microwave).
      2. Reduce costs (less material is used, the punched-out metal holes can be melted down and used again).
      3. To let air or water pass through easily (so that water doesn't accumulate inside a satellite dish).

      However, as far as I know, the holes in a faraday cage are not put there to boost

  • Not quite microwave (Score:4, Informative)

    by Ge10 ( 803950 ) on Wednesday October 26, 2005 @07:56AM (#13879487)
    This has been around for a long time. In the book "Spycatcher" by ex-MI5 agent Peter Wright, he describes a bug used by the KGB to spy on the American ambassador in Hawaii (I think). There was a metal membrane hidden inside a wooden carving, which would passively vibrate with sounds in the room. A strong RF beam of around 900 MHz (details are hazy again, and it's not quite microwave) was directed towards the office from a fair distance away, then the signal would be minutely modulated and reflected by the metal membrane. It was able to work for several years, and this was in the 1960's. You can only guess what's available now.
    • There was a metal membrane hidden inside a wooden carving, which would passively vibrate with sounds in the room. A strong RF beam of around 900 MHz (details are hazy again, and it's not quite microwave) was directed towards the office from a fair distance away, then the signal would be minutely modulated and reflected by the metal membrane.

      Is there a replica of this in the NSA crytography museum?
    • The whole story. [spybusters.com] It was found in the fifties in American embassy in Moscow. The metal post was stuck in a carved wooden eagle schoolchildren gave to the ambassador. When found, the device was called "The Thing" because the US couldn't figure out what it was for. Peter Wright of MI5 eventually figured it out.

      I guess with the processing power and algorithms of NASA, the US can do this microwave espionage without a metal post. Hrm.

  • Electronic signal cleaning technhiques (Score:3, Informative)

    by kilodelta ( 843627 ) on Wednesday October 26, 2005 @08:02AM (#13879507) Homepage
    I guarantee they're using a MASER. You can thank RADAR pioneers from M.I.T. and Bell Labs for that.

    That being said it is easily defeated. For example - short wavelengths below 1cm start resonating with water vapor. That's why doppler radar has been such a boon to meteorology.

    But there are ways to stop it. Metal impregnated and grounded cement walls that are, oh, 6 to 8 feet below grade level would be reasonably safe. Of course don't put any windows, just ventilation.

    And if you're really that much of a target they'd bug the place before they resorted to using microwave to listen in. BTW, for a good fantasy view of using microwave to peek in I highly recommend watching "The Siege" with Denzel Washinton and Tony Shaloub.
    • And if you're really that much of a target they'd bug the place before they resorted to using microwave to listen in.

      Consider other applications, like a bunch of bad-guys have just created a hostage situation. You couldn't have known, and bugged the place, before-hand. But you bring in this device and can immediately start listening to what's going on inside. I think the fact that it is portable and easy to setup is what makes it so useful.

      Not to mention that paranoid people will search (and maybe fi
  • but wouldn't the simple precaution of turning up the radio/TV defeat this ? Humans can pickout certain noise and filter out everything else quite easily. How does tinfoil and other "vibrating surfaces" fare in this regards ?

  • old hat (Score:2, Informative)

    by fliptout ( 9217 )
    The president at one of my former companies was a colonel in the Army Security Agency. He used to tell me all sorts of things, including how the Russians bombarded the US embassy with radiation to get signature signals back. And this was in the 60s or before. The surveillance technology available to intelligence now must be quite interesting.

  • Perverting Technology (Score:2, Informative)

    by rhkaloge ( 208983 )
    I actually know researchers who have been working with what they call "wall penatrating RADAR" and it sounds a lot like this - it more detects movement and sound then being able to image what is in a room. The big things they claim it would be good for is detecting fires from a distance, finding people trapped in places (it can detect a heartbeat) and, yes, seeing that sniper around the corner. I don't think they considered audio survallence, or at least they never told us about it. But I suppose once yo
    • You are (are you?) probably talking about Microwave Impulse Radar, the miracle technology that was supposed to change our lives years ago. It's tiny bursts of microwave radar, able to be transmitted/received at short ranges at tiny power levels by an on-chip transmitter.
      Here's a typical article about MIR [llnl.gov]. Last I read, there were legal battles about shoddy treatment of potential vendors by the LLNL. Slashdot readers would probably do well to track this technology!

      A taste of this from http://www.eurekalert [eurekalert.org]
  • Any chance this could affect those with pacemakers?
  • Can you mount the detector on top of a handheld railgun??

  • Old news (Score:4, Informative)

    by Technician ( 215283 ) on Wednesday October 26, 2005 @09:22AM (#13879950)
    A wodden copy of the Great Seal of the United States was bugged. Part of the seal was used as a diaphram and was used as a passive resonant reflector. This would pass most bug sweeps as the device was not active, but passive. When painted with a 330 Mhz signal, it would modulate it.

    The only update in the article is now they use microwaves and common materials already in a room.

    Details here;
    http://www.spybusters.com/Great_Seal_Bug.html [spybusters.com]

    This bug is was delivered in 1946 and discovered in 1952.
  • And here I thought the link would lead to a pic of a room of nudists ...
  • Looks like people will have to return to having meetings in the shower.

Slashdot Top Deals

I have hardly ever known a mathematician who was capable of reasoning. -- Plato

Close