Big Brother Gets X-Ray Vision

What’s more important – privacy or security? The question has been at the forefront of political policy debate since 9-11. Nobody wants to be the victim of a terrorist attack, but where do we draw the line between security measures and infringements of liberty?


 The ThruVision T5000 is a new security camera that can see through clothing, detecting explosives, liquids, narcotics, weapons, plastics, and ceramics, but not your body parts (or so they say).


As with much of technology, the ThruVision was created for an entirely different purpose than that for which it is being used. British astronomers created the technology to see past the dust and clouds that were blocking their view of dying stars. The special camera picks up “Terahertz” rays or T-rays, that are “naturally emitted by all objects and can pass through fabric or even walls”.

It’s pretty useful technology for high-security areas like airports, and as such, is slated for use in airports.  But this device is also being considered for use in general public areas.

The proponents’ arguments range from potential prevention of terrorist attacks that don’t occur in airports/airplanes, to reduction of time spent waiting at security checkpoints (outside airports).

The opponents’ point is that this is an invasion of privacy when used in a general public area. At an airport, you know beforehand that you will be searched, you’re aware of the search while it’s happening, you understand why it’s happening, and you’ve consented to it. With the ThruVision, literally, you’re walking down the street with a pack of gum in your pocket and the camera’s picking up the foil wrapper. And you have no idea.

Has big brother gone too far?

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  1. In a public place, there’s very little legal expectation of privacy. You can be photographed, videotaped, and your voice recorded, and there’s nothing you can do about it (short of hiding in your basement).

    That said, it’s hard to imagine that the same thing applies to the space inside your clothes. My guess is that using this device to peer inside a subject’s clothing would be considered a search under U.S. law, and would be subject to the same restrictions as a physical search. There would have to be some specific suspicion about an individual before he or she could be scanned.

    Note to self: wandering about with that machine-gun wielding cyborg shark under my coat is about to get a whole lot trickier.

  2. “and your voice recorded”

    Actually, this is not universally true. In the US, it varies from state to state. Some allow recording of voices without consent and some do not.

    You may remember from the Monica Lewinsky flap, that Linda Cropp got into a spot of difficulty because she had recorded Lewinsky’s voice over the phone without permission, which was not allowed in the state of Maryland.

    I also recall a story years ago about a teenage boy who was shooting videos consisting of shots up the skirts of women. He was arrested, but they discovered that they had nothing to charge him with since videotaping people without permission was not illegal. Audiotaping people’s voices without permission was illegal, but his videos had no sound.

  3. I’m no legal expert, so correct me if I’m wrong, but I don’t think it’s illegal to record someone. It’s just that the recording can’t be used as evidence in a court of law unless the person gave consent to be recorded.

    Of course the whole thing confuses me. I mean, you could have an outright confession and you can’t use it as evidence?? And if so, what’s the point of the proverbial “wire”?

  4. The worst part is that dichotomy between security/privacy is false, or at least a stretch of the real trade off to be really secure. Much of the measures that are accepted by many people, in the name of security, have more to do with control then with security.

    Gather too much information, for instance, is bad for security. It is very hard to sort out the data. It is a better approach to get less information that is to the point.

    Much of the controls and fall into the let’s make people feel secure, and do little in real security. For this T-Ray to be useful it would have to recognize dangerous materials automatically, with a very low false-positive rate.

    The problem is that the vast majority of the population are not terrorist, even if you put people that are normal (or should I say dumb) criminals that want to board an airplane with a gun, that would still be a tiny percentage of the people. So the operator have to stare at the screen witch he knows that nothing is getting out.

    If the T-Ray operates by it self, it should not give to many false negative because this would also create a distrust in the red flag that machine generate.

  5. Stacey: That’s kind of what I was referring to in my comment. If law enforcement can articulate specific suspicions about an individual, they can get a court order allowing them to make clandestine recordings, either by wiretap or by “wire.”

    In an emergency, they can conduct the surveillance and get the court order later, but they can’t use the evidence at trial without convincing a court that they had a good reason to believe that the person they where recording was doing something dangerous or criminal. Without that individualized suspicion, the recording would be inadmissible as evidence.

    My point was that the T-ray scanner is analogous. If the police want to, they can simply plug into a phone line and listen to every conversation it’s carrying. Likewise, they could just T-ray scan every person in a park on the off chance that one of them might be carrying a suitcase nuke. But unless they convince a judge that they had a good reason to individually scan the guy with the vial of weaponized anthrax glued to his taint, they won’t be able to use the results of the scan (and probably anything that resulted from it) in court.

  6. “Expectation of privacy” is the key concept here. It is perfectly legal to record anything that does not violate someone’s expectation of privacy. That goes for public places, and (with permission of the owner) private property. Generally, that means you can’t have cameras in places like bathrooms or dressing rooms, where people expect not to be observed. Anything else is fair game.

    Some states have proposed laws limiting public photo/video rights in order to stop things like up-skirt voyeurs. In every case I’m aware of, these laws have been thrown out for being too broadly defined.

    This particular technology… It will probably have to be decided by the courts whether it is an invasion of expected privacy to see what objects a person is concealing in their clothing.

  7. Stacey: Hope it helped. As a non-scientist, there are so few things in the Skepchick oeuvre that I can comment on with any kind of authority. When I recognize a legal issue that I have some knowledge about, I tend to slobber all over it. =)

  8. Well, ain’t a lawyer and don’t even play one on TV. So absolutely anything I say on the topic should be taken with at least a grain of salt. I’m going on things I have read in newspapers…and often remembered years later at that.

    I do think that there are often more restrictive laws about recoding a phone conversation than there are about recording someone’s voice live.

    “Of course the whole thing confuses me. I mean, you could have an outright confession and you can’t use it as evidence?? And if so, what’s the point of the proverbial ‘wire’?”

    The concern with recorded evidence is that it can be manipulated and used out of context. Sure, the person sounds like he is outright confessing, but is he really doing so when taken in context? For a simplistic example, does “I killed her” mean I am guilty of murder or does it mean that I just beat my sister at checkers.

    If the person must agree, it formalizes the process and gives more reliable evidence.

  9. TheCzech – I’m in the same boat as you – not a lawyer and don’t even play one on TV. :) And that’s a good point you made about the recording being taken out of context.

    LBB – Thanks for slobbering on my post. You definitely helped clear things up for me.

  10. All audio and vodeo is suspect, really. Just go watch any summer action flick and see what a dedicated person with a top-end computer can do. It’s honestly barely more reliable than eyewitness testimny except that most people don’t have the time, money, or skill to manipulate it well.

  11. My state, as with many others, makes it absolutely illegal to record a conversation with another person without that persons explicit permission. I also believe if one person in the conversation is in another state that it is a violation of federal law. However it is not illegal to photograph or video another person without their consent.

    The “investigative” reporter in this state would be breaking the law if they recorded sound with video of an unsuspecting person. However I’ve hardly ever seen this prosecuted as it’s stock and trade with most local investigative reporters.

  12. “All audio and vodeo is suspect, really. Just go watch any summer action flick and see what a dedicated person with a top-end computer can do. It’s honestly barely more reliable than eyewitness testimny except that most people don’t have the time, money, or skill to manipulate it well.”

    Very true…though it takes an incredible amount of painstaking effort to make a fake video that an expert cannot detect. One bit of pixels that don’t line up properly and you’re cooked.

  13. If we EMIT T-rays, much as we reflect light and propagate pressure waves through the air, since the law permits the recording of two of the three in public, it stands to reason that the third would fall under the same rules.

    But if the surveillance equipment is shining T-rays at the subject and recording the bounce, then that’s perhaps a different subject.

    (Then again, night vision security cameras often emit and reflect IR off people…)

    Well, break out the tinfoil!

  14. Meh. People will just have to live with the knowledge that you can’t conceal things inside your clothes anymore, unless you make them of tin foil. Tin foil stops T-rays, doesn’t it?

    People used to portray life in the 21st century showing us all wearing shiny silver jumpsuits. Now we know what kicks off that fashion trend!


  15. I’m a sophomore physics major at Rensselaer Polytechnic Institute. Our physics department has done a lot of the pioneering work on applications of Terahertz-frequency radiation, and the researchers gave a lecture about their applications in one of my classes last year. He had some nice pictures of one of his assistants, as seen without his clothing via a T-Ray system (of course with strategic locations blurred out). As I remember they were also working on a suitcase-sized imager and had gotten to the prototype phase.

  16. The “expectation of privacy” standard, mentioned above, is the ultimate standard for what measures are lawful (read: constitutional) for the government to use.

    As for taping phone calls, federal law does prohibit taping phone calls where neither party knows they are being taped (unless you are, well, the federal government or you are a law enforcement agency with a warrant). Twelve states prohibit taping phone calls where only one party knows he/she is being taped. Otherwise, anyone can tape a conversation he/she is participating in. Whether you could use that as “evidence” in a courtroom is a whole different story. See

    Isn’t this all part of a bigger question – Did the terrorists “win” on 9/11? I agree with the statement that privacy and security are not necessarily mutually exclusive. But this all seems like one small aspect of a cumulative effect of our privacy, our commerce, and our choices being limited by fear.

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