If you set off a gas chromatograph for nitroglycerine and then say you have heart tablets then you'll be fine. He obviously set off a specific trigger AND couldn't account for it (although they clearly tried to get him to).

Back in the 70s or 80s a group of friends in Britain were sentenced for participating in a terrorist act because they set off an explosive test. They spent years in prison before it was determined that it was a false positive caused by the coating of a popular brand of playing card.

> If you set off a gas chromatograph for nitroglycerine and then say you have heart tablets then you'll be fine. He obviously set off a specific trigger AND couldn't account for it (although they clearly tried to get him to).

That isn't what that line of interrogation was for. The TSA goons probably don't know anything about chemistry or how their machine works, they were simply trying to rattle him and get him to say something incriminating.

Specifically: when somebody says, several different ways, "why are you setting off my explosive detector?" what you do not want to say is "I don't know! I don't have any explosives!" Because it will elicit a response indicating that nobody was accusing you have of having explosives, why are you being so defensive, etc. etc.

Too bad they couldn't even tell him what set it off, since he clearly did not remember:

  "I can’t think of anything. What does it say is triggering the alarm?" I asked.

  "I’m not going to tell you! It’s right here on my sheet, but I don’t have to tell you what it is!" he exclaimed, pointing at his clipboard.

''EDIT: formatting''

Not letting him drink water or whatever is simply inhumane. Not giving him information is simply a judgment call or policy decision. Perhaps it is against policy to reveal which exact molecules their machines react to.

So what you're saying is all I have to do is carry heart tablets and then I can pass nitroglycerine through security? Don't get me wrong, I'm sure it's more complicated than that. But I can't help but feel that if someone really wanted explosives to get onto a plane then they wouldn't try walking it through passenger security. Or maybe they'd just say the magic words that indicate a false positive and walk straight through.

One time I brought peanut butter in my luggage. It looks like plastic explosive on the scanner so they have to open it and test it. Our teacher actually advocated that we bring it and those 36 packs of AA batteries because they look like plastic explosives and bullets, respectively. He really liked to mess with the TSA.

This was post 9-11, I don't know how we didn't all get arrested.

Hmmm Peanut butter doesn't even seem like a liquid, aerosol, or gel, though the TSA would probably put it in that category these days.

> (In both cases, due a heart medication that apparently triggers false positives).

Presuming that this was nitroglycerin, then in some sense it's not a false positive at all. It's a dessert wax and a floor topping! https://en.wikipedia.org/wiki/Nitroglycerin

>dessert wax

What happens if you put a candle in one of these desserts and let it burn down to the food? (Or it tips over)

Extended explosion swabbing -- and improved and more discrete equipment -- came about after the failed attempt to blow up Northwest Airlines Flight 253 to Detroit in 2009 (an almost tragedy that many quickly forget).

In earlier iterations of spam filters, it would simply prefix the subject with [SPAM], just as explosion detectors caught lots of things and they quickly dismissed them. As it got better it started moving them to a spam folder. Now it simply moves them directly to deleted. Of course the same thing happens with explosion detectors, where initially it picked up many similar compounds, and eventually started getting much more discrete, and the probability that it actually caught something of significance went from "not really" to "might actually be something real".

Traveling in 2013 is not the same as traveling in 2002. Traveling in New York City is not the same as traveling in Austrlia. All of these are factors that influence the probability that technology is a viable input, and the corresponding risk factors.

> Of course the same thing happens with explosion detectors, where initially it picked up many similar compounds, and eventually started getting much more discrete, and the probability that it actually caught something of significance went from "not really" to "might actually be something real".

Unless you've got some hard data on false positives, I don't believe it for a minute. As far as I can tell the equipment's warning value has gone from "almost certainly not explosives" to "almost certainly not explosives."

That doesn't make the equipment useless (well, it might) but it'd be nifty if the people operating it understood its pretty obvious limitations. Remember why we're even having this conversation.

I don't have hard data (the actual details are often considered confidential), but for the marketing claims of the various makers who all trumpet greater selectivity and the rejection of false positives. Which makes sense, as security is a huge, incredibly competitive industry, and these people are all competing for the world's paranoia dollars.

Because the TSA gained nothing wasting their time on this. There are the normal conspiratorial claims among the comments that someone triggered the "brown guy" button just to harass him (again, only someone who has never been near a large North American city could say such a thing), for what? What did the TSA, NYPD, FBI, and whoever else gain from this giant waste of time?

Something triggered on a molecule or taggant that they couldn't easily exclude, so they tried to help him assist them in excluding it. He couldn't, so they had to exhaust all avenues.

Unless they have countless agents and countless rooms, this isn't something they do with any regularity at all.

> I don't have hard data (the actual details are often considered confidential), but for the marketing claims of the various makers who all trumpet greater selectivity and the rejection of false positives. Which makes sense, as security is a huge, incredibly competitive industry, and these people are all competing for the world's paranoia dollars.

Putting aside the merit of the idea of that the government bidding process ends with purchase of the best product, it's worth noting that just like with the government agents, the manufacturer isn't actually liable to anyone who suffers when its machines produce a false positive. Insofar as the manufacturer has any incentive to improve in this regard, its incentive comes from the same people who are putting on this security theater.

> Because the TSA gained nothing wasting their time on this. [blah blah] What did the TSA, NYPD, FBI, and whoever else gain from this giant waste of time?

Not sure why you threw this in here but it's so wrong that it's kind of hard to know where to begin. First, the superficial and obvious: TSA and NYPD are paid overtime. They had MONEY to gain from this exercise. Their financial incentives are exactly opposed to those of the person they are detaining.

Less superficial, perhaps equally obvious: a bureaucracy does stuff because that's the stuff the bureaucracy does. It's a big, mindless machine whose prime directive is to continue to exist. Everyone understands that they need to be seen to be DOING SOMETHING, and there are plenty of true believers who think doing that something is the most important thing in the world. That's the reason for some much of the crud we deal with now.

You might have made the mistake of thinking we're dealing with fully rational actors here. Congratulations if you've never worked for a bureaucracy and you don't get any of this.

> Something triggered on a molecule or taggant that they couldn't easily exclude, so they tried to help him assist them in excluding it. He couldn't, so they had to exhaust all avenues.

Orwell would be proud.

So you're anti-government and cynical. Welcome to about 99% of the online community.

There are people who actually want to blow up planes. There have been a number of attempts. These machines detect the things that are found in bombs.

There are a lot of examples of "security theater" (moreso in the private industry, it should be noted, like the ridiculously useless badges and disaffected employees at most office buildings), but explosives material detectors most certainly are not. One day we'll walk down a Total Recall type hall and it will know who we are and everything on or about us, but until then we have some inconveniences.

And groan, good old Orwell makes a cliched showing. Yes, we all read 1984 in grade school. Pulling it out as a trope to anything the government does (even where entirely rational and related to an actual threat, and overwhelming painless and transparent) is boorish internet pundit behavior.

> So you're anti-government and cynical.

No, you don't get to label me that easily. (why do you want to?) I believe there is a differentiation to be made between good government and bad government. Security services CAN be made to work.

> And groan, good old Orwell makes a cliched showing. Yes, we all read 1984 in grade school.

I was responding to a specific statement of yours which was pretty spectacularly stupid. I'm not saying YOU are stupid, and I think maybe you can get a handle on why it's so creepy and classically Orwellian. Let's examine it:

> Something triggered on a molecule or taggant that they couldn't easily exclude, so they tried to help him assist them in excluding it. He couldn't, so they had to exhaust all avenues.

"They tried to help him assist them in excluding it." They tried to help him assist them. Are you getting it yet? They were just trying to help him! Against his will they detained him and tried to compel him to do something, but they were just trying to help. To help HIM! To help him ASSIST them, why wouldn't he want to assist them? It'd be awfully suspicious if he didn't want to assist them. Every good person likes to help and to assist, am I right?

They tried to force him to solve a problem that they created with their own machine and they weren't going to let him go about his business until he did it. For his own good. In what sense is your take on that - the wording, at least - not Orwellian?

> Pulling it out as a trope to anything the government does (even where entirely rational and related to an actual threat, and overwhelming painless and transparent) is boorish internet pundit behavior.

Since there wasn't an actual threat, and the process wasn't painless, and since I certainly wouldn't and haven't "pulled it out as a trope to anything the government does" it's hard to understand what the heck you're talking about.

> What did the TSA, NYPD, FBI, and whoever else gain from this giant waste of time?

Employment, pensions, and control.

I don't think explosion swabbing detectors are operating in a free market: they are built off funds from government contracts. There isn't much reason to expect a similar pace of innovation as for email servers.

Why not? Money is money, after all. The contracts don't say how to do it, they say what to do. There's plenty of room for competition in these types of things, from how to meet the Performance Work Statement all the way to how to setup the internal org. structure to most efficiently handle contract compliance overhead.

I don't think any airports had 'explosive detectors' before 9/11.

I was searched with one around the year 2000, IIRC, at the San Francisco airport. I think it was pretty experimental.

edit: there might have been a similar setup at Orly in France in 1997, come to think of it. The striking thing there was the soldiers with rifles (just 3 of them, but walking around) and the way they searched one of my grandmother's bags when the x-ray showed something that looked like a grenade. (it was glass in a weird shape) They were friendly and had a sense of humor about it, and it didn't slow us down, which all made a big difference.

Most European airports have had those as long as I can remember (definitely since the mid 90s).

Maybe bomb detectors but the explosive detectors ('puffers') are relatively new as far as I know.

It was a huge political budget fight in the 90s. Clinton/Gore published a white paper detailing the threat of terrorism as the biggest threat to national security. They called for the fancy new detectors and what-not at airports.

The Republicans, who controlled Congress, said that the big threat was from nukes from unfriendly states (later dubbed 'the axis of evil') didn't permit the funding and instead increased 'Star Wars' funding (anti-missile tech).