Once they've determined he isn't carrying actual explosives he shouldn't be considered a threat anymore. The detection machine might single you out for additional searching, but once the search is complete you should be free to go.
This. The craziness of "he set of the detection machine but it's clearly a false-positive, but now that he's on our radar let's grill him in case he just happens to be a terrorist" should be obvious to anyone.
Yes, IMHO it comes from this: What would be on the news if he was a terrorist and they find out that he actually set off the explosives detector before doing his deed? So basically their response is more about fear of embarrassment (to an extreme) than actual effectiveness.
It is also about a lack of accountability. There is no penalty for going to town on the guy - for them its just a more exciting day on the job - for him it's a humiliating loss of personal autonomy.
> for them its just a more exciting day on the job
Yes. Get into their mentality. The lower ranks are underpaid would be burger flippers and In-and-Out. The go through their boring day pushing prodding people. If they get to "interrogate" someone or humiliate him or show off their power just like a bully would in the cafeteria you betcha they'll take advantage of that.
>Once they've determined he isn't carrying actual explosives he shouldn't be considered a threat anymore. //
Because people who handle explosives and cover it up when questioned, and aren't involved in handling explosives in their day job, are completely to be trusted?
Surely once they've determined he isn't carrying explosives they need to be sure as possible, if he claims not to have been around any explosives, that he's telling the truth; in order to reduce the risk that he's going to use explosives in an illegal way and/or manner dangerous to life. Don't people who're manufacturing explosives in secret deserve at least a passing glance to see what they're doing with them.
It looks here like they checked his apartment to corroborate his statements.
Now if they've established there are no traces of explosive present - for example they confirm the cause of a false-positive - that's different.
The problem with your line of thought is that you trust that machine to be somewhat reliable. We don't _really_ learn what set off the machine, but the author's guess is an over the counter spray..
If that's the high tech "You need to endure this process for the greater good, since the machine claims you're a threat" world you like to live in, I .. opt out. That thing is obviously next to useless and probably as effective as a look in the eyes of the stranger, with your gut deciding if he's going to stay put for the rest of the day or if he's allowed to move on.
IFF we had a reliable, working test with little to no false positive due to f*ing everyday stuff (or .. bad luck, being a 'random' match), THEN you might have a point. Right now, you don't.
>your line of thought is that you trust that machine to be somewhat reliable //
And your problem is you assume the machine isn't reliable. So then if it's set off, you just say "ah well, it's probably a false reading". At that point you just obviated the purpose of the machine.
Yes we don't learn whether it was the permethrin (? can't certainly recall the name) but the people who did the sweep of his apartment confirmed that there were no other indications of explosives manufacture [or you can plump for the slightly less cynical - 'the questioning confirmed he was not a threat'].
There's likely always going to be some false-positives: the needs of the many, yadda, yadda.
>IFF we had a reliable, working test with little to no false positive due to fing everyday stuff* //
Can you post your source and the pertinent stats for the number of false-positives for explosives detection at airports in the USA please.
Our friend Bayes and his theorem can help us here. Suppose you have an HIV test which is 95% accurate in detecting if you are HIV positive or not. The HIV rate in the US is about 0.3%.
If you subject a random American to this HIV test and the test result is positive, what is the probability that that person has HIV? I wont do the math, but the right answer is about 2%. Since the prevalence of HIV is so low it doesn't matter how accurate the test it, it will still generate many times more false positives than true ones.
Same thing with bombs. The number of American air passengers/year is about 800 million/year and of them, at most 5 are carrying explosives. Even if the bomb detector is 99.9% accurate it will generate thousands of false positives for each real bomb it catches.
It turns out when you actually get tested for HIV, they do two tests. One has a high false positive rate but a low false negative rate. If that comes positive, they do a second test that's the other way around.
It also turns out that we don't test everyone for HIV. In what I am sure is some form of irony, we probably test more folks for carrying bombs than we do for having HIV. When the numbers show there are more folks with HIV in America than there are those carrying bombs.
What that means is that people who trip these explosives detectors should be politely treated while it is determined whether or not they actually have explosives, since they are likely not really carrying explosives.
But this doesn't mean that scanning for explosives is a bad idea, or that people should just be merrily flagged to go on their way, otherwise what is the point of doing any screening?
After all, the vast, vast majority of passengers are just trying to go from point A to point B so each and every single scanning method will generate thousands of false positives every year.
That's weird. You're turning the argument on its head.
YOU started supporting the process and said something like
Don't people who're manufacturing explosives in secret..
Well, based on what evidence? The machine that detects chemicals here? It seems that this supports my claim, you think that machine is 'working' and somewhat reliable. Without having provided any kind of proof or source, by the way.
The article, the author, proceeds to talk about potential chemicals to set off the detector (and we had more posts like this over the years, for example from people working with plants, farmers etc). Chemicals you're able to get everywhere.
If that is a known issue and this machine can beep if
a) you've built a bomb
b) you've moved your plants from inside the house to your garden
then you should reevaluate the idea of this particular test in the first place. The author writes that one participant in that theater claimed to know the exact substance that triggered the detector. Really? In that case it should be possible to
- dismiss the idea, it's stupid. That stuff? Everyone can buy it
- ask disguised/hidden questions to reveal if he used one of the gazillion things that might trigger this warning and leave the man alone
The option
- keep him, make him feel like a criminal, treat him in an inhuman (no water..? Really?) way for as long as it takes to break into his appartment
is really not on the list of things you can rationally describe as necessary. That's insane.
Ah, well. I come up empty handed at the end and cannot provide a source for the reliability of the detectors used in the US of A. I guess that makes my whole post moot. Obviously you don't need to provide the same thing, since "It's used at the airports, certainly it works!"?
> If that is a known issue and this machine can beep if a) you've built a bomb, b) you've moved your plants from inside the house to your garden, then you should reevaluate the idea of this particular test in the first place.
It's more complicated than that. Anecdotal evidence suggests the trace analysis machine has a very low false positive rate. The fact that agents are trained to re-run the test repeatedly also suggests the machine has a very low false negative rate.
Given a sufficiently low false positive and false negative rate, the right answer may be, if it repeatedly triggers on a passenger, to question that passenger further.
Of course, with increasing reliability of the test comes increasingly severe questioning when the test repeatedly fails. In theory you want the level of the response to be commensurate with the reliability of the test. A perfect test convicts you as soon as you fail it. An imperfect test such as this requires humans to actually follow-up and investigate the failure.
The tactics, ethics, and legality of the how that investigation proceeds... I think that's another matter entirely, from whether we should be employing trace analysis in airports in the first place.
> It looks here like they checked his apartment to corroborate his statements.
Checked? That's being charitable. You mean it's okay to break into someone's apartment without a warrant and steal shit? What happened to the rule of law? Having said that, we don't know who broke in or what happened.
Not that the whole story isn't appalling, but why would you assume the break-in was without a warrant?
"This guy set off explosive detectors at the airport. He claimed it was because of chemicals he used while moving. We'd like to check his story out by searching his place." Looks to me like that could convince a judge.
I didn't say anything about trust. What I meant was he wasn't a threat to that particular flight. If the aim of the TSA is to keep a plane from blowing up, they've already accomplished it. Anything beyond that is just a fishing expedition. Given that they know their tests will detect compounds that aren't explosives this seems over the top.
