Correct. In the US, the TSA is just a government jobs program for the lowly skilled or unskilled. It's all security theater.

TSA Chief Out After Agents Fail 95 Percent of Airport Breach Tests

"In one case, an alarm sounded, but even during a pat-down, the screening officer failed to detect a fake plastic explosive taped to an undercover agent's back. In all, so-called "Red Teams" of Homeland Security agents posing as passengers were able get weapons past TSA agents in 67 out of 70 tests — a 95 percent failure rate, according to agency officials."

https://www.nbcnews.com/news/us-news/investigation-breaches-...

It's about making people feel safe.

We're not rational beings, so what do you do about an irrational fear? You invent a magical thing that protects from that irrational fear.

You're orders of magnitude more likely to die in a road accident, but people don't fear that. They fear terrorist attacks far more.

You can't protect against an opponent who's motivated to learn the inherent vulnerabilities of our systems, many of which can't be protected against due to the laws of physics and practicality - short of forcing everyone to travel naked and strapped in like cattle, with no luggage. And even then, what about the extremist who works for the airline?

So you invent some theater to stop people from panicking (a far more real danger). And that's a perfectly acceptable solution.

Not a chemist…but if someone can carry on 3 bottles at 3.4 ounces each, now they have 10 ounces.

Two people do it and it’s 20 ounces. All within the “TSA Standard.”

This is where the liquid limit never made sense to me…if we were serious about keeping these substances off of planes, we would limit the total liquid…right? Or require that any liquids get checked.

I just don’t see how per-bottle liquid limits are anything close to deterrent for motivated attackers…but they sure are deterrent for me when I forget that I put a hotel water bottle in my bag.

On one hand, I think it's a valid criticism to say it's security theatre, to a degree. After 9/11, something had to be done, fast!, and we're still living with the after effects of that.

On the other hand: defence in depth. No security screening is perfect. Plastic guns can get through metal detectors but we still use them. Pat downs at nightclubs won't catch a razor blade concealed in someone's bra. We try to catch more common dangerous items with the knowledge that there's a long tail of things that could get through. There's nothing really new there, I don't think?

It was always theater, Bruce Schneier did a great set of blogs and tests back in the 2001+ time showing flaws throughout the process. At the same time, he pointed out that humanity had already adapted their response to airplane hijackings _that day_ (the Pennsylvania flight). An airplane exploding from a bomb is definitely scary, but not as scary as airplanes being turned into missiles by a few suicidal passengers.

After 4 years of Russia/Ukraine, does anyone think that a terror group would take down an airliner with anything other than a drone? Why take any operational risk of actually going through security?

> The motivation behind the liquid limits is that there are extremely powerful explosives that are stable water-like liquids.

The limits were instituted after discovering a plot to smuggle acetone and hydrogen peroxide (and ice presumably) on board to make acetone peroxide in the lavatory. TATP is not a liquid and it is not stable.

https://en.wikipedia.org/wiki/2006_transatlantic_aircraft_pl...

I'm fine with some liquid potentially being explosives, but the fact that security just throws them all in the same bin when they confiscate them makes me think that not even they believe it makes any sense.

Also, why 100ml? Do you need 150ml to make the explosive? Couldn't there be 2 terrorists with 100ml + 50ml? All these questions, so little answers...

From my understanding, the new CT machines are able to characterise material composition using dual-energy X-ray, and this is how they were able to relax the rules.

most of airport security rests on the notion of going over a series of long tests will elicit unusual (fear, stress) responses from malicious actors and these can then be flagged for even thorougher checks which will then eventually lead to discovery, banning or removal of luggage

so it's not the test accuracy by itself but rather then the fact that these tests are happening at all

Are these chemicals freezable? Because TSA lets through large quantities frozen matter that is liquid at room temp. E.g. you can bring through a liter of hot sauce if it's frozen when it passes through TSA.

> Average people have never heard of them because they aren’t in popular lore.

Everything I know about liquid explosives I learned from Die Hard 3.

I remember reading something around the time these prohibitions against liquids were rolled out that said none of the two-part liquid explosives were powerful enough to take down a plane unless you were carrying an unusual amount of liquid to be traveling with, or storing your liquid in an unusual way. For instance, there should be no reason you couldn't carry an ordinary sized bottle of shampoo in your luggage. No idea how accurate this is, maybe somebody could set this straight?

These liquids show up as slightly different colors in the new CT scan machines and this can finally be reliably detected by software.

This is also why a bunch of airports no longer ask you to take electronics out of your bags.

Is the capability of these explosives at a safe level if the liquid precursors are less than 3.5 fl ounces? If they are still capable of blowing a hole in the fuselage with less than 3.5 fl ounces then the limits on fluids are still pointless.

Modern airport x-ray machines use two frequencies and then estimate the density of objects and liquids. In theory, the can tell the difference between water and vodka. I wonder if the change reflects trust in this tech?

> It would be great if governments were more explicit about precisely what all of this theater is intended to prevent.

The liquids requirement was in response to a famous (at the time) plot by people in Britain to smuggle a two part liquid explosive onto the plane. So the context was, at the time, obvious and needed no explanation.

If those explosives are extremely powerful then do the limits actually prevent using them to do damage inside an airplane though? TSA isn't even effective at preventing you from bringing on sharp metal objects as long as they aren't particularly knife shaped.

They don't believe these liquids are actually dangerous, otherwise they wouldn't just throw them in a bin near the queue.

> It would be great if governments were more explicit about precisely what all of this theater is intended to prevent.

That is a good statement. It IS a theater. So, the point for it IS the theater. The "evil terrorists" is just the scapegoat wrapper, similar to how officials in the EU constantly try to extend mass surveillance and claim it is to "protect children".

If you have access to nitric acid you don't need any obscure lore. 3 ounces of a simple concoction a high school chemistry student could make is enough to blow a hole in an airplane. You also stand a good chance of blowing yourself up on the way to the airport.

So how does that explain I can take 10 100ml bottles and an empty 1l bottle through security but not 1 full 1l bottle?

Maybe I'm being naive, but it has always seemed pretty trivial to me to use the post-security shops to assemble something that will meaningfully damage the aircraft - so the whole thing smacked of theatre.

I think the idea is that the new scanners they have are capable detecting liquid densities better so that they can actually tell the difference now?

>is reminds me of the chemical swipes done on your bags to detect explosives.

I've also had this done on my dialysis port at some airports here in India :-|

> extremely powerful explosives that are stable water-like liquids.

My understanding is that those are detected by the bag swabs.

I _thought_ that this was to stop people mixing their own explosives _on_ the plane? There was a whole court case in the UK about how people had smuggled it onboard and then were going to make it in the toilet.

They would need and ice bath, which is somewhat impractical.

One theory that I've had for a while with regards to the no liquid policy is that it was somehow introduced by the food vendors on the other side of security, who want you to buy a drink and some food after you pass through.

I believe the "theater" is needed precisely for this - to catch bad actors. There could just be a long queue with some blind dog and scary looking guy at the end. What it still does is makes a bad guy sweat, plan against it and etc. You just can't have free entrance for all. However you will never prevent state actors or similar with any kind of theatre because they will always prepare for it.

Israel strips you naked and rubs the swipe between your legs thoroughly. Source: friend.

Won't asking people to take a swig solve a bunch of those issues?

> These explosives can be detected via infrared spectroscopy but that isn’t going to be happening to liquids in your bag

There are more ways to find them. Look up Z score. TL; DR New detectors can discriminate water from explosives. Old ones couldn’t. None of them are doing IR spectroscopy.

Schiphol at Amsterdam had this for a year or so, you could bring any type of liquid and leave everything in the bag. But they reverted the liquid rule, if I remember correctly, because of the confusion it caused.

I thought the point of replacing all the xray scanners with CT scanners was to be able to detect this sort of thing?

Security theater and conditioning people into accepting invasions of privacy

Because the theater raises the threshold.

Is a open flame enough to ignite those liquids and don't they need something to press against to "explode" and not just cause a giant flame like gasoline?

In Zurich, you can buy Swiss army knives in the secure zone.

The security theatre is there to make people feel safe.

It's about emotion not logic.

2 part liquid explosives featured heavily in Die Hard with a Vengeance.

OP is talking about (mostly) TATP here. It's very easy to make, harder to detect with traditional methods and potent enough to be a problem. It's also hilariously unstable, will absolutely kill you before you achieve terrorism, and if you ask people on the appropriate chemistry subreddits how to make it you'll be ridiculed for days.

> . This reminds me of the chemical swipes done on your bags to detect explosives. Those swipes can only detect a narrow set of explosive chemistries and everyone knows it.

Meanwhile, you get swabbed, the machine produces a false positive, the TSA drone asks you why the machine is showing a positive, you have no fucking idea why, and they just keep swabbing until they get a green light and everyone moves on with life.

If I recall correctly, it was WIDELY reported by sane, savvy people that no such liquid agents existed that could be combined onboard in this way.

Are there examples you can point to?

how does it add confusion?

if normal people don’t know, criminals/terrorists do, and the materials are commonplace but not screened for, then everything about the current approach is wrong.

and when has a plane been brought down by the evil explosives or stable liquids in recent memory?

so the theatre put in place is just that, huh?

> This reminds me of the chemical swipes done on your bags to detect explosives. Those swipes can only detect a narrow set of explosive chemistries and everyone knows it. Some explosives notoriously popular with terror organizations can’t be detected. Everyone, including the bad guys, knows all of this.

I used to work at a place that sold a lot of fertilizers. We mostly sold stuff like Monoammonium phosphate or potassium nitrate.

One time while cleaning out a back storage room I came across an open bag of ammonium nitrate. I picked that thing up, carried it around, putting it on a cart and wheeling it around kicking up a lot of dust, all the kinds of stuff that you’d expect while cleaning out a storage room.

A day or so later I got on a plane and they swabbed me and my bag before doing so. I was startled when I didn’t raise any alarms.

I was completely under the misguided impression they something like ammonium nitrate would be detected on a person if they had handled it within a few days of being tested and that would have to explain myself.

I wonder if the improvements can detect trigger mechanisms better rather than testing the liquid itself.

And yet .. nothing ever seems to happen! Even though it's so easy.

That means one of at least two things. Either the terrorists are stupid and easily impressed by the security theater. Or there are just not that many bad ombres out there trying to take down airplanes. Or something else I can't think of.

Any thoughts?

I assume the logic was:

1) People demand the government be accountable for their failing to protect them

2) Government responds by increased giving the appearance of protecting them, since that creates more lowest-common-denominator sense of feeling safe than the government actually protecting them does; votes protected

3) Complaints of "security theatre" don't alter the above - they just have to wait until people have forgotten their fear while very slowly, bit by bit, without it being noticed, stop doing the nonsense

Or put simply: "terrorists win"

Its not just for explosives, by the way. Its also for solvents - for example, mercury, which could be used to weaken the airframe very easily.

Well, I watched the video of some former Delta Force officer, who said that you can sharpen your credit card to make a deadly weapon out of it. Let's ban credit cards in the airplanes.