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Your first points should really be addressing active Terahertz radiation and its effects on living things. Reference: http://en.wikipedia.org/wiki/Terahertz_radiation

The summary is that we don't know enough about terahertz radiation to draw any solid conclusions yet, and there is at least one reputable source pondering, "How Terahertz Waves Tear Apart DNA": http://www.technologyreview.com/view/416066/how-terahertz-wa...

Do you know how much power is emitted by the terahertz-wave scanner as two antennas are swept across your mid-section in close proximity?

Here are some responses to your other points about mm-wave:

Passive mm-wave scanners do not produce radiation

Passive mm-wave scanners are not used in airports and not relevant to this discussion.

You'll pick up far more radiation on the flight itself at a fairly low 5 mrem (50 µSv)

Also, irrelevant as the xray body scanners have largely been removed from US airports due to their safety concerns. The EU has also banned the use of those scanners. The study that you cite is for radiation applied to the entire body mass, while the xray body scanners applied all of the ionizing radiation only to the outer layer of the body (skin + some bones + male reproductive organs + brain).

Thanks for bringing the MIT article to my attention. I wouldn't say I referenced the type of radiation, but was just a little less specific. The only source for the article you pointed to (http://arxiv.org/abs/0910.5294) was a model, not an experiment or test.

Given the potential for DNA damage, though, it would be silly of me not to agree that more research should be done to see whether this model theory of "resonant effects" have any significant real-world impact.

On the one hand, I agree that these machines are unlikely to be a public health risk, and I further agree with you on the real problems here.

On the other, I think that that it's misleading to compare risks you choose with risks that are forced upon you. That's part of what has people up in arms here; it's clear that the TSA didn't really care about safety or privacy when they started with this, so I'm ok with people being deeply suspicious about the "no, really, it's all safe and private now" shtick.

Also, I think this is dangerous: "By analogy, you don't need to study the health effects of every single x-ray machine because we know what x-rays do. You just need to know the machine's dosage and wavelength."

It's worth considering the THERAC-25, a device with software bugs that killed 3 people: http://en.wikipedia.org/wiki/Therac-25

There's always a difference between what a machine is supposed to do and what it actually does. None know that better than HNers. Given that this is a novel technology rushed into production using giant government contracts to satisfy the security theater apparatus, it's reasonable to worry whether corners were cut, worries suppressed, or facts buried.

I'm happy to trust my dentist's x-ray machine because he's a licensed, trained medical professional who's focused on healing, and who plans to stand right next to it for a couple decades. None of that applies in the TSA situation.

I think the TSA scanners are probably fine anyhow, and I've used them happily when I don't have time to be obstreperous. But I don't fault people who refuse to trust the TSA on this.

> The machines no longer store or display images of your body - they store and display images of a generic body with the data received from you.

How about a bit of warranted cynicism: How do we know the high-res versions aren't being stored? It would be useful for them to do so, the images have been stored in the past, and the announcements don't mention storage, only display.

(For those unfamiliar: High-res versions have to be taken, they definitely do exist. The vague images the TSA personal see are the result of the original images being run through ATD (sometimes called ATR or AID) filters that boil the original image down to the important parts.)

Storing the original high-res versions would probably be fantastically useful. It would provide a good data source for real-world benchmarks and operational feedback for L3, but most enticingly it would provide an audit trail for post-incident analysis so investigators could re-examine the scanned data for a targeted individual.

Given that this is the age where, by default, we store everything and analyze it later, people did talk about storing the images, even if it was entirely low key. It's just too obviously useful.

I was looking into this recently, and I couldn't find anything about the new L3 ATD machines that mentioned whether the images are stored. The parent comment's links say nothing about it and I couldn't find anything else that did, including the L3 ProVision ATD product page[1].

It certainly seems strongly implied that the images are not stored. We read phrases from L3 like "processed by software without human intervention", but that sounds somewhat suspiciously specific. OK, no one is definitely and actively looking at it, but what about potentially and passively? Is it just bad wording on their part, or is someone actually trying to leave a loophole?

If they're going to scan us in a way we feel is invasive, is it too much to get some sort of assurance that the images are being handled properly? Frankly, an audit of the machines would be more than in proper order, given that it's handling sensitive data that needs to be carefully handled.

Can anyone point out something I've missed? Is there anything that talks about image storage, not just display?

[1]: http://www.sds.l-3com.com/advancedimaging/provision-at.htm

I find it odd that we can exist as a community here at HN- with reasonable dialog and exchange of ideas, but yet we can have people like you who wholesale swallow these scanners as reasonable and worth accepting.

The TSA has a history of mismanaging the use of these scanners. This includes the actual operation of the devices as well as the maintenance of the devices. They don't provide meaningful security. All encroachments into our privacy should be fought on principle.

Stop moralizing so I don't have to copy your writing style to make a point. We can disagree on topics. There shouldn't be anything off limits at Hacker News.

The tactics you are employing in your writing style are obvious to any critical reader. Do not embarrass yourself by attempting to shame the community be association. We're all above average intelligent here. Reasonable people can disagree. Unreasonable people try to leverage shame. The community of opt-outers at HN is actually a reflection of the thoughtfulness of the average Hacker News Reader. Thoughtful people can disagree about Nginx vs. Apache, just the same as they can disagree about the value of TSA's naked body scanne^d^d privacy disintermediation proxies.