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Did The TSA and JetBlue Deny Travel For Looking Muslim During Ramadan? No

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Re: Did The TSA and JetBlue Deny Travel For Looking Muslim During Ramadan? No

#211

Post by lambda »

vidarh wrote: post #130
lambda wrote: post #99

Earlier quoted context omitted.

> The most logical conclusion that I can come to is that a law enforcement agent searched Mukerjee's apartment and probably took the photo so that it could be scanned or for some other reason but accidentally forgot to put it back. Have you ever considered that his landlord could have come into the apartment to make sure it had been cleaned up properly by the outgoing tenants (remember, he had moved in the night befo…

> Have you ever considered that his landlord could have come into the apartment to make sure it had been cleaned up properly by the outgoing tenants If that's legal in the US, or something one might expect, that's almost more shocking to me than the original story. If any of my past landlords had entered my flat without permission, I would have called the police on them, with good cause.

The laws in the US vary by state (and sometimes by city within the state).

He was living in NYC, so I'll quote their rules. From http://pubadvocate.nyc.gov/landlord-watchlist/tenant-rights:

> In general in New York City, a landlord may only enter a tenant’s apartment for three reasons: emergency repairs, non-emergency repairs or improvements, and apartment inspections. Emergency repair requires no advance notice to the tenant. However, access for non-emergency repairs and improvements requires a minimum of one week’s advance written notice, and access for inspection requires a minimum of 24 hours advance written notice.

If he was on vacation, then 24 hours written notice for inspection could consist of putting the notice on or under his door, waiting 24 hours, then going in for the inspection and removing the notice.

I've had my landlady enter my apartment without permission or notice before, and it was a little bit creepy, but I let it slide since she was such a nice lady. She wasn't some owner of a big apartment complex or anything, just had a second house down the street that she rented out, I think mostly so she could store all of the extra furniture she picked up at flea markets and couldn't fit into her own house. In fact, the reason she had entered our house was to stash a few lamps that she did't want her sister to sell at a yard sale, so we came back one day and there were extra lamps sitting around.

Re: Did The TSA and JetBlue Deny Travel For Looking Muslim During Ramadan? No

#212

Post by glenra »

mintplant wrote: post #111
InclinedPlane wrote: post #50

Earlier quoted context omitted.

That's an extraordinarily shitty excuse.

Oh come on . > These events include Mr. Mukerjee becoming further agitated and aggressive after testing positive for explosives, as well as him repeatedly reaching for his not-yet-manually-searched bag. > However,multiple statements by TSA personnel reference Mr. Mukerjee repeatedly grabbing for his bag after he was told not to touch it. > While false positives are not unusual for ETD, it is unusual a person and thei…

> it is unusual a person and their items could fail so many times using different testing equipment.

So maybe it's finding something true. BFD. You look in the bag, verify there's no explosive there, and let him through.

Maybe the bag had fireworks in or near it at some point. Or magician's supplies. Or a chemistry set. Or any number of other things. There are a dozens reasons why a bag might actually have been near explosives or chemicals that are similar enough to explosives or explosive precursors that the test would correctly show positive.

Nobody cares whether the test result was an error or a "correct" reading based on something that IS NO LONGER IN THE BAG - either way, you let him through. Why the hell not?

Re: Did The TSA and JetBlue Deny Travel For Looking Muslim During Ramadan? No

#213

Post by glenra »

weland wrote: post #162
mintplant wrote: post #111

Earlier quoted context omitted.

Oh come on . > These events include Mr. Mukerjee becoming further agitated and aggressive after testing positive for explosives, as well as him repeatedly reaching for his not-yet-manually-searched bag. > However,multiple statements by TSA personnel reference Mr. Mukerjee repeatedly grabbing for his bag after he was told not to touch it. > While false positives are not unusual for ETD, it is unusual a person and thei…

One of the things you get when you have a horde of untrained, uptight civilians dressed in uniforms is an incredibly unprofessional behaviour from someone who is supposed to do law enforcement. The agents did several things that escalated the whole deal, things which a cadet would have immediately understood. To quote just a few: > These events include Mr. Mukerjee becoming further agitated and aggressive after testi…

> We will have to remove all items in another room,

Searching the bag in another room has too much abuse potential. If travelers let bags out of their sight even for a few minutes the TSA could easily steal or break anything of value in there with no accountability. So the existing procedures mostly don't allow that - searching has to take place in the presence of the passenger.

Re: Did The TSA and JetBlue Deny Travel For Looking Muslim During Ramadan? No

#214

Post by glenra »

etchalon wrote: post #126
Amadou wrote: post #109

Earlier quoted context omitted.

So they have their procedures. But that raises the question - what is the point? Let's assume the threat is real, someone with nefarious intent is not-detained, escorted to outside the building and left to his own devices. What is to stop him from simply turning around, re-entering the building and going through a different screening station? I'm pretty sure the answer is "security theater."

Well, if you'd read the rest of the article, you'd see the procedures are designed to ensure that, if he's going to do that, he's doing it without any implement of harm on him, or least not one the TSA can find. Also, pointing out that it's impossible to deter a truly convicted person from a heinous act does not mean all deterrents are pointless. Yes, MUCH of what the TSA does is theater, and doesn't do much to keep…

> Yes, MUCH of what the TSA does is theater, and doesn't do much to keep us safe. Yes, much of it is theater.

ALL of what the TSA does is theater, and it actively makes us LESS safe. Their actions cause over a thousand unnecessary deaths a year by making air travel less convenient and more expensive so people who drive when they would otherwise fly get killed in auto accidents. There is no evidence they have saved even a single life with any of these precautions, much less the thousand-a-year they'd need for the billions we spend on them to be a break-even proposition.

Re: Did The TSA and JetBlue Deny Travel For Looking Muslim During Ramadan? No

#215

Post by glenra »

reso wrote: post #29

Airport security is frequently humiliating. I myself have been nearly reduced to tears just by customs agents when crossing the border on business. However, this man set off a bomb detector. He set of the machine that detects bombs, repeatedly. After that event, nothing Mr. Mukerjee reported is particularly surprising, and I would expect to have a similar experience if I set off the same detector. I don't believe his…

> However, this man set off a bomb detector. He set of the machine that detects bombs, repeatedly. After that event, nothing Mr. Mukerjee reported is particularly surprising, and I would expect to have a similar experience if I set off the same detector.

I wouldn't. My bag often sets off the bomb detector repeatedly; when that happens they just search it and send me on my way. It's no big deal. If the bag sets off the bomb detector repeatedly, the most likely reason for it is that the bag was at one point in contact with some chemical that is related to an explosives precursor. And that's OKAY. It's no big deal. You check whether the bag has explosives in it RIGHT NOW, and if it doesn't, you send the guy on his way!

(FWIW, I think I've triggered due to (a) flash paper (a magician's supply), (b) fireworks (of the safe-and-sane variety). In both cases the offending material wasn't actually present, but it had been IN the bag or IN my clothes in the prior week)

Re: Did The TSA and JetBlue Deny Travel For Looking Muslim During Ramadan? No

#216

Post by glenra »

DannyBee wrote: post #19
xdissent wrote: post #5

Why does "keeping in mind that false positives with ETD are not uncommon" sound unsettling to me?

If you've got a better way to distinguish trace amounts of explosive chemicals, i'm sure they'd love to pay you millions for machines to test it :) http://onlinepubs.trb.org/onlinepubs/tcrp/tcrp_rpt_86v6.pdf looks relavent here. Completely skimming it, the test sites had false positive rates of 0.6 - 1.8%. I'd classify that as "not uncommon".

> Completely skimming it, the test sites had false positive rates of 0.6 - 1.8%.

In other words, the test is almost completely useless. Given how low the base rate of terrorists sneaking through bombs is, a positive test result on one of these machines is >99.9% likely to be a false positive.

Let's do the math. We'll assume there are never any false negatives and just look at the positive results. Let's simplify "0.6-1.8%" and just call that "1%". Out of 100,000 bags, let's assume that ONE contains a bomb being snuck through by a terrorist. 1/100,000 is our postulated base rate of terrorism. 1/100 is our false positive rate on the test.

So let's put 100,000 bags through the machine. There will be 1,000 false positives and one true positive. which means that if some bag "tests positive for explosives" the odds are a-thousand-to-one against that being a valid result.

"But," I hear you cry, "we RUN IT THROUGH AGAIN when we get a positive result!"

Sure, that would work GREAT if false positive results were COMPLETELY RANDOM. But they're not. More likely than not, the false positive is being triggered by something that is or was actually in the bag. So when you run it again, there's a good chance that it'll trigger again. The "false" part of "false positive" is that the thing in the bag that it's triggering on...isn't an explosive. It's just some other chemical.

Re: Did The TSA and JetBlue Deny Travel For Looking Muslim During Ramadan? No

#217

Post by tptacek »

glenra wrote: post #216
DannyBee wrote: post #19

Earlier quoted context omitted.

If you've got a better way to distinguish trace amounts of explosive chemicals, i'm sure they'd love to pay you millions for machines to test it :) http://onlinepubs.trb.org/onlinepubs/tcrp/tcrp_rpt_86v6.pdf looks relavent here. Completely skimming it, the test sites had false positive rates of 0.6 - 1.8%. I'd classify that as "not uncommon".

> Completely skimming it, the test sites had false positive rates of 0.6 - 1.8%. In other words, the test is almost completely useless. Given how low the base rate of terrorists sneaking through bombs is, a positive test result on one of these machines is >99.9% likely to be a false positive. Let's do the math. We'll assume there are never any false negatives and just look at the positive results. Let's simplify "0.6…

Just a nit: a high false positive rate makes the test operationally expensive, but not useless.

Re: Did The TSA and JetBlue Deny Travel For Looking Muslim During Ramadan? No

#218

Post by glenra »

tptacek wrote: post #217
glenra wrote: post #216

Earlier quoted context omitted.

> Completely skimming it, the test sites had false positive rates of 0.6 - 1.8%. In other words, the test is almost completely useless. Given how low the base rate of terrorists sneaking through bombs is, a positive test result on one of these machines is >99.9% likely to be a false positive. Let's do the math. We'll assume there are never any false negatives and just look at the positive results. Let's simplify "0.6…

Just a nit: a high false positive rate makes the test operationally expensive , but not useless .

It's not just the high false positive rate, it's the combination of a high false positive rate with a really low base rate. (If there were a lot more terrorists, the test might be worth doing!)

The combination of those two facts means that getting a hit on explosives gives you almost no increase in information. Any look at plausible numbers makes the test nearly useless at finding explosives, though it's still at least theoretically possible the test could serve as a sort of deterrent, albeit primarily a deterrent against movie-plot threats.

My guess is that the true purpose of this test is to make the people who sell explosives-testing equipment comfortably well off. Any other purpose would be served roughly as well with a box that triggered based on random number selection.

Re: Did The TSA and JetBlue Deny Travel For Looking Muslim During Ramadan? No

#219

Post by tptacek »

glenra wrote: post #218
tptacek wrote: post #217

Earlier quoted context omitted.

Just a nit: a high false positive rate makes the test operationally expensive , but not useless .

It's not just the high false positive rate, it's the combination of a high false positive rate with a really low base rate. (If there were a lot more terrorists, the test might be worth doing!) The combination of those two facts means that getting a hit on explosives gives you almost no increase in information . Any look at plausible numbers makes the test nearly useless at finding explosives, though it's still at le…

I am extremely, bitterly familiar with the base rate fallacy (I was an intrusion detection researcher, and spend 4+ years working on statistical anomaly detection the Internet backbone).

The fallacy doesn't make a value judgement. It points out something counterintuitive about the accuracy of a filter or test. That thing is important, but not dispositive. If the base rate is low and the false positive rate is percentagewise high but the overall number of hits is manageable, low-power statistical tests can have utility as pre-filters.

I have the same thought every time I go through airport security ("whoever designed this probably doesn't know about the base rate fallacy"), but if the system is only ejecting 1-2 candidates per station per hour for expensive "offline" screening, it's not untenable.

Re: Did The TSA and JetBlue Deny Travel For Looking Muslim During Ramadan? No

#220

Post by smsm42 »

etchalon wrote: post #204
smsm42 wrote: post #194

Earlier quoted context omitted.

The agents should be trained not only to look for something, but to handle false positives - which given how few terrorists are out there would be the vast majority of cases they will ever encounter. Moreover, for a random TSA agent false positives are probably all he'd ever encounter. Unlike the police, TSA deals in vastly overwhelming majority with innocent people who they are meant to protect , not harass. They ar…

Because the "abuse" in this case was utterly reasonable given the circumstances and the person's behavior. This is pretty rare for the TSA (the number of stories where they had no cause to be idiots is much MUCH higher than cases where they did).

How is it reasonable? They knew or should have known he's not a terrorist in first 15 minutes. What were they doing for three and a half hours? Why did they ask him about praying and problems with female attendants and such?
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