# Has TSA screening at US airports stopped a single terroristic plot since its establishment? **URL:** \ **Category:** Factual Questions\ **Created:** [January 8, 2019, 9:08pm UTC](https://boards.straightdope.com/t/has-tsa-screening-at-us-airports-stopped-a-single-terroristic-plot-since-its-establishment/827429 "2019-01-08T21:08:08Z")\ **Posts on this page:** 20\ **Page:** 3
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [January 9, 2019, 5:46pm UTC](https://boards.straightdope.com/t/has-tsa-screening-at-us-airports-stopped-a-single-terroristic-plot-since-its-establishment/827429/41 "2019-01-09T17:46:42Z")
[Moderating] I’ve been getting a few reports that this thread should be moved to GD. From what I can see, most posters are making a reasonable effort at keeping responses factual. So long as that continues, the thread can stay here. If it does not continue, it will be moved or closed. ---
**Author:** ![iamthewalrus\_3](https://avatars.discourse-cdn.com/v4/letter/i/258eb7/32.png) [@iamthewalrus\_3](https://boards.straightdope.com/u/iamthewalrus_3)\ **Post date:** [January 9, 2019, 7:00pm UTC](https://boards.straightdope.com/t/has-tsa-screening-at-us-airports-stopped-a-single-terroristic-plot-since-its-establishment/827429/42 "2019-01-09T19:00:33Z")
> [@JB99](#): > > Prove it. I laid out my argument in the post you took that quote from. I think it’s pretty clear. Do you have something to add? ---
**Author:** ![Voyager](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/voyager/32/133_2.png) [@Voyager](https://boards.straightdope.com/u/Voyager)\ **Post date:** [January 9, 2019, 7:27pm UTC](https://boards.straightdope.com/t/has-tsa-screening-at-us-airports-stopped-a-single-terroristic-plot-since-its-establishment/827429/43 "2019-01-09T19:27:49Z")
> [@UltraVires](#): > > I agree with your statement, but I’m not sure what your point is. Freedom should not be a one way ratchet. Event X happens so we restrict your freedom a little. Then Event Y happens so we do it a little more. And we keep looking for Event X. > > There will never be another successful aircraft hijacking in the United States. The old school “give them what they want and everything will be okay” was forever put to rest on 9/11 and will never happen again. So why conduct security as if that is the goal? In the Cuban hijackings for the most part the plane went to Havana, the hijacker got off, was thrown in jail by Castro, and the plane returned with no one getting hurt. I’m not sure that an unsuccessful hijacking due to the plane crashing or people getting shot would be better than that. We haven’t had unsuccessful hijackings since 9/11 either. We had successful ones after screening and before 9/11 due to lax security in terms of sharp object. This was no secret - I’ve heard a George Carlin routine from before 9/11 where he says that the security system is stupid for allowing knives om. They should have hired him to run security. I certainly agree that measures like locking the cockpit door are good and have helped. And I’m not against better screening. But success speaks for the effectiveness of the current system, annoying as it is. ---
**Author:** ![JB99](https://avatars.discourse-cdn.com/v4/letter/j/439d5e/32.png) [@JB99](https://boards.straightdope.com/u/JB99)\ **Post date:** [January 9, 2019, 7:36pm UTC](https://boards.straightdope.com/t/has-tsa-screening-at-us-airports-stopped-a-single-terroristic-plot-since-its-establishment/827429/44 "2019-01-09T19:36:06Z")
> [@iamthewalrus\_3](#): > > I laid out my argument in the post you took that quote from. I think it’s pretty clear. Do you have something to add? I think it’s pretty clear that you (and the other posters with a similar argument) are assuming facts not in evidence. It is very difficult to prove intent. I find the idea that “Because no terrorist attacks happened, it proves no one intended to commit a terrorist attack,” to be an absolutely absurd and unsupportable argument. ---
**Author:** ![DrCube](https://avatars.discourse-cdn.com/v4/letter/d/a3d4f5/32.png) [@DrCube](https://boards.straightdope.com/u/DrCube)\ **Post date:** [January 9, 2019, 10:15pm UTC](https://boards.straightdope.com/t/has-tsa-screening-at-us-airports-stopped-a-single-terroristic-plot-since-its-establishment/827429/45 "2019-01-09T22:15:16Z")
> [@Riemann](#): > > How could we possibly know about the deterrent effect? How can we possibly know whether or not my tiger repellent undergarments are working? Nevertheless I wouldn’t propose spending billions of taxpayer dollars on a federal tiger repellent undergarment program to protect Americans from tigers. If such a program already existed, I wouldn’t accept “we couldn’t possibly know whether it is working” as an argument to keep the program in operation. > [@bardos](#): > > TSA is incredibly effective. They confiscated and destroyed my 200ml shampoo bottle, thus preventing… not sure what TSA is incontrovertibly winning the war on clean hair. ---
**Author:** ![iamthewalrus\_3](https://avatars.discourse-cdn.com/v4/letter/i/258eb7/32.png) [@iamthewalrus\_3](https://boards.straightdope.com/u/iamthewalrus_3)\ **Post date:** [January 9, 2019, 10:25pm UTC](https://boards.straightdope.com/t/has-tsa-screening-at-us-airports-stopped-a-single-terroristic-plot-since-its-establishment/827429/46 "2019-01-09T22:25:12Z")
> [@JB99](#): > > I think it’s pretty clear that you (and the other posters with a similar argument) are assuming facts not in evidence. It is very difficult to prove intent. I find the idea that “Because no terrorist attacks happened, it proves no one intended to commit a terrorist attack,” to be an absolutely absurd and unsupportable argument. That’s… not my argument at all. My argument is that no one would attempt a knife-based attack any more because it’s a stupid tactic that won’t work. And we _know_ it won’t work because the window for it working didn’t even last a whole day. Therefore, we don’t need to take knives away, and taking them away doesn’t help prevent anything. ---
**Author:** ![Nava](https://avatars.discourse-cdn.com/v4/letter/n/da6949/32.png) [@Nava](https://boards.straightdope.com/u/Nava)\ **Post date:** [January 10, 2019, 3:10am UTC](https://boards.straightdope.com/t/has-tsa-screening-at-us-airports-stopped-a-single-terroristic-plot-since-its-establishment/827429/47 "2019-01-10T03:10:01Z")
> [@Voyager](#): > > When is the last time a plane got diverted to Cuba? That was pre-TSA, yes, but the same thing. It’s not like screening started on 9/11. But that was in great part a matter of the geopolitical landscape changing. The US is the only country where non-jihadist terrorism has gone _up_ since the Wall fell. And while there were enough “take me to Havana” hijackings to become a meme before the general public had a word for them, it wasn’t either the only location (I just found a newspiece about a [Havana-Madrid plane diverted to Miami in 1996](https://elpais.com/diario/1996/07/27/espana/838418422_850215.html), for example) nor something which happened as often as it got joked about. ---
**Author:** ![DSYoungEsq](https://avatars.discourse-cdn.com/v4/letter/d/c6cbf5/32.png) [@DSYoungEsq](https://boards.straightdope.com/u/DSYoungEsq)\ **Post date:** [January 10, 2019, 3:47am UTC](https://boards.straightdope.com/t/has-tsa-screening-at-us-airports-stopped-a-single-terroristic-plot-since-its-establishment/827429/48 "2019-01-10T03:47:56Z")
> [@iamthewalrus\_3](#): > > That’s… not my argument at all. > > My argument is that no one would attempt a knife-based attack any more because it’s a stupid tactic that won’t work. And we _know_ it won’t work because the window for it working didn’t even last a whole day. Therefore, we don’t need to take knives away, and taking them away doesn’t help prevent anything. The fact that it did not work on United Flight 93 does not mean it cannot work ever. The situation might be different with, say 15 knife-wielding terrorists, rather than 4 or 5. The situation might be different if they threatened to slit the throat of the flight attendants one by one, until they got access to the cockpit. Etc. I agree it’s unlikely to work, but that doesn’t mean I don’t want them screening for it. ---
**Author:** ![puzzlegal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/puzzlegal/32/3827_2.png) [@puzzlegal](https://boards.straightdope.com/u/puzzlegal)\ **Post date:** [January 10, 2019, 4:01am UTC](https://boards.straightdope.com/t/has-tsa-screening-at-us-airports-stopped-a-single-terroristic-plot-since-its-establishment/827429/49 "2019-01-10T04:01:31Z")
> [@JB99](#): > > _You_ had no intention. Can you prove that none of the others had criminal intention? No, but I think it’s unlikely. Can you prove that even one of them did? > [@JB99](#): > > The purpose of TSA is to prevent people from bringing weapons and other prohibited items on board the plane. We see, indisputably, that they do this many thousands of times each year. Therefore TSA accomplishes it’s purpose with at least some success. I’m sorry, if their purpose is just to steal shampoo and pocket knives from people, I have no idea why we are supporting them with taxpayer money. Oh, wait, it’s because their purpose is actually to prevent terrorist attacks to airplanes. Not to confiscate stuff. Sorry. This is not evidence they are doing any good at all. > [@JB99](#): > > As many others have already pointed out, it is impossible to know the intent of the person. So as with **iamthewalrus** above, we are stuck trying to infer that a confiscated weapon was not intended to be used in terrorism, therefore TSA is somehow ineffective. (???) > > We have no good way of knowing whether a person is an inept terrorist, a forgetful traveler, whether they aborted their terrorist plot after their weapon was discovered, or if the actual terrorists were so intimidated by security procedures that they just didn’t even bother trying. > > Anyone involved with the security industry learns very quickly that deterrence is an impossible metric to assess. I find it utterly baffling that someone would assume that NONE of the weapons confiscated ever had a criminal intent. (As if that somehow makes it okay to bring a gun on a plane?) > > Also, as I noted above, last year 198 weapons were found which were deliberately concealed (eg in a hidden pocket or false container). Can you prove to me that zero of those intercepted weapons were intended to be used in terrorist plots? No, but having hidden a “weapon” myself (successfully) I think there’s a decent chance that those people just wanted to take their weapons wherever they were going. > [@JB99](#): > > The logic of saying “The fact that it was discovered proves it was not a terrorist plot, because if it was a terrorist plot it would not have been discovered,” is the most boneheaded and fallacious chain of logic I’ve ever heard. So then if intercepting thousands of weapons has nothing to do with preventing terrorism, what _is_ your standard for success? You’ve eliminated the entire possibility of success with your sweeping definition that all positive outcomes be automatically excluded from consideration. > > If an MP had stopped Nidal Hassan and discovered his handguns, would you say he is not a terrorist? Or that he did not have terrorist intent? Of course! We’d just say, “Oh, he lives in Texas where lots of people have guns and he just forgot they were in his car.” And he’d have gotten a small penalty and we’d never know his name. > > Please, prove to me that none of these people had intent to commit a crime. Because unless you can figure out how to open up someone’s skull and look inside, you can’t. That’s true. I can’t prove it. But I’d like some evidence more than “hey, look, they confiscated a lot of knives”. A few years ago, the security experts tried to make it legal to fly with knives again. Probably not with big swoard-like things, but small pocket knives were going to be legal. Because now that the rule is “fight back” there’s really nothing much a terrorist can do with a knife. The new rule was announced. And nervous members of the public (and flight attendants, who sometimes deal with drunk and unruly passengers) got all bent out of shape, and we were stuck with a continued useless ban on small pocket knives. It’s security theater. The solid door is for real. The ban on guns (which pre-dates 9/11) is for real. The ban on liquids might even be for real, although we were supposed to get better scanners – that could tell the differences between explosives and all the usual things people want to fly with – about two years ago, and somehow haven’t. ☹ Has TSA screening stopped a single terrorist plot? There’s really no way to know. But it seems very unlikely, and I’ve yet to hear any plausible argument for them having done so. ---
**Author:** ![puzzlegal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/puzzlegal/32/3827_2.png) [@puzzlegal](https://boards.straightdope.com/u/puzzlegal)\ **Post date:** [January 10, 2019, 4:03am UTC](https://boards.straightdope.com/t/has-tsa-screening-at-us-airports-stopped-a-single-terroristic-plot-since-its-establishment/827429/50 "2019-01-10T04:03:10Z")
> [@DSYoungEsq](#): > > The fact that it did not work on United Flight 93 does not mean it cannot work ever. The situation might be different with, say 15 knife-wielding terrorists, rather than 4 or 5. The situation might be different if they threatened to slit the throat of the flight attendants one by one, until they got access to the cockpit. Etc. > > I agree it’s unlikely to work, but that doesn’t mean I don’t want them screening for it. If the cockpit door is locked, what good does it do to slit the throats of the flight attendants? As soon as the pilot brings the plane down, lots of armed men will enter and those perps will be escorted to prison. ---
**Author:** ![TSBG](https://avatars.discourse-cdn.com/v4/letter/t/77aa72/32.png) [@TSBG](https://boards.straightdope.com/u/TSBG)\ **Post date:** [January 10, 2019, 4:33am UTC](https://boards.straightdope.com/t/has-tsa-screening-at-us-airports-stopped-a-single-terroristic-plot-since-its-establishment/827429/51 "2019-01-10T04:33:24Z")
I think we should stop to consider that the post-hijacking wave, pre-9/11 security regime was pretty successful. I credit a number of things for this, including the then-existing security procedures and things we’ll never know in detail like what the FBI and CIA did to forestall such attacks. And remember the US and specifically its president were warned that al-Qaeda wanted to use planes in a a terror attack, but the president chose to do nothing. So, plane-attacking terrorists got very lucky–_once_. As a result we all take off our shoes. ---
**Author:** ![Alley\_Dweller](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alley_dweller/32/430_2.png) [@Alley\_Dweller](https://boards.straightdope.com/u/Alley_Dweller)\ **Post date:** [January 10, 2019, 4:54am UTC](https://boards.straightdope.com/t/has-tsa-screening-at-us-airports-stopped-a-single-terroristic-plot-since-its-establishment/827429/52 "2019-01-10T04:54:03Z")
> [@puzzlegal](#): > > If the cockpit door is locked, what good does it do to slit the throats of the flight attendants? As soon as the pilot brings the plane down, lots of armed men will enter and those perps will be escorted to prison. If the hijackers managed to get into the cockpit, their goal is to die, not to fly safely to Kabul. I don’t think they will be deterred by the prospects of getting arrested. Slashing the throats of 10 or 20 flight attendants and passengers mid-air would be a very terrifying act of terror and, hence, help them achieve their goals. No less terrifying than running a truck through a street fair in Europe. I doubt the typical load of passengers can react quickly enough to stop them before they kill a bunch of people on the airplane. Or is it OK if they kill a bunch of people on the plane as long as they don’t take over the cockpit and get arrested afterward? ---
**Author:** ![Great\_Antibob](https://avatars.discourse-cdn.com/v4/letter/g/e47c2d/32.png) [@Great\_Antibob](https://boards.straightdope.com/u/Great_Antibob)\ **Post date:** [January 10, 2019, 5:35am UTC](https://boards.straightdope.com/t/has-tsa-screening-at-us-airports-stopped-a-single-terroristic-plot-since-its-establishment/827429/53 "2019-01-10T05:35:02Z")
> [@Alley\_Dweller](#): > > Or is it OK if they kill a bunch of people on the plane as long as they don’t take over the cockpit and get arrested afterward? That’s more than a small goalpost shift of the purpose of TSA security screening. The main point of TSA screening is to prevent aircraft hijacks and bombings. Due to other, simpler measures (mostly a secured cockpit door), small knives can’t be used to hijack an aircraft unless the crew does something very dumb and against security procedures. And neither can small knives be used to blow planes up. It isn’t possible for any screening, even with perfect detection, to prevent all possible violent human interactions aboard aircraft. That’s flat out impossible. That’s an unrealistic and unreasonable expectation to set on the TSA, no matter how effective or not they are at it. Somebody may claim that’s the putative goal, but perfection is always more of an aspiration than realistic goal. A person set on harming random chosen people is going to manage it. We want to make it harder to accomplish this on aircraft and to mitigate damage. Damage mitigation is largely accomplished already. And we can always do things to make it harder to hurt people, but these should be realistic rather than based on what feels good but not actually useful. Prisoners, despite even more stringent security measures and inspections in prisons, manage to create makeshift shivs from a variety of common items. The idea that confiscating small knives represents a significant improvement in passenger safety from a planned attack involving stabbing and slicing defies reality and experience. ---
**Author:** ![iamthewalrus\_3](https://avatars.discourse-cdn.com/v4/letter/i/258eb7/32.png) [@iamthewalrus\_3](https://boards.straightdope.com/u/iamthewalrus_3)\ **Post date:** [January 10, 2019, 5:47am UTC](https://boards.straightdope.com/t/has-tsa-screening-at-us-airports-stopped-a-single-terroristic-plot-since-its-establishment/827429/54 "2019-01-10T05:47:37Z")
> [@DSYoungEsq](#): > > I agree it’s unlikely to work, but that doesn’t mean I don’t want them screening for it. The problem is that the screening has a real cost. The TSA collected [4 billion dollars](https://www.tsa.gov/for-industry/security-fees) in fees last year. There are _so many_ better ways to use 4 billion dollars to save people’s lives, even if you limit it to preventing terrorist attacks. Yes, I know that all $4 billion isn’t spent on knife prevention. But some meaningful amount _is_. And that’s just the monetary cost. How much of our lives do we waste standing in stupid lines waiting for screening that doesn’t make us meaningfully safer? How much hassle and bureaucratic idiocy and invasion of personal space and not having a fucking pocket knife when you need one while traveling. It’s hard to see that as anything but a tremendously wasteful misallocation of effort. People are very bad at risk analysis. ---
**Author:** ![bardos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bardos/32/1069_2.png) [@bardos](https://boards.straightdope.com/u/bardos)\ **Post date:** [January 10, 2019, 7:30am UTC](https://boards.straightdope.com/t/has-tsa-screening-at-us-airports-stopped-a-single-terroristic-plot-since-its-establishment/827429/55 "2019-01-10T07:30:00Z")
The whole TSA/airport experience reminds me of 1930s Germany. YMMV ---
**Author:** ![Lord\_Feldon](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lord_feldon/32/341_2.png) [@Lord\_Feldon](https://boards.straightdope.com/u/Lord_Feldon)\ **Post date:** [January 10, 2019, 8:42am UTC](https://boards.straightdope.com/t/has-tsa-screening-at-us-airports-stopped-a-single-terroristic-plot-since-its-establishment/827429/56 "2019-01-10T08:42:22Z")
> [@TSBG](#): > > So, plane-attacking terrorists got very lucky–_once_. As a result we all take off our shoes. That was actually because of a plane-attacking terrorist (Richard Reid) who was thwarted by the existing security, which made it very difficult to get a real detonator through. > [@bardos](#): > > The whole TSA/airport experience reminds me of 1930s Germany. YMMV Yes, how horrible. Six million Jews, they had to put their bags through an X-ray and then they lived the rest of their lives in peace. So sad, never again. :rolleyes: ---
**Author:** ![UltraVires](https://avatars.discourse-cdn.com/v4/letter/u/ecccb3/32.png) [@UltraVires](https://boards.straightdope.com/u/UltraVires)\ **Post date:** [January 10, 2019, 1:08pm UTC](https://boards.straightdope.com/t/has-tsa-screening-at-us-airports-stopped-a-single-terroristic-plot-since-its-establishment/827429/57 "2019-01-10T13:08:52Z")
> [@Cheesesteak](#): > > Let’s look at the data we have. > > 198 concealed weapons found last year > Security tests imply that the TSA fails to find weapons at least 50% of the time. > > This suggests, in the conservative case, that approximately 200 concealed weapons were NOT found last year. > > It is impossible to PROVE they were not found, but if a system fails spectacularly in undercover tests, it is highly unlikely that they succeed fantastically during normal times. > > So, if 200 weapons were not found, and there weren’t any terrorist attacks on planes with these weapons, I’d say the smart money is on the other 198 not being terrorist plots as well. This. The problem is that once we start down this discussion, others get confused and think that I am advocating for guns on planes or don’t care if there are guns on planes. It seems there is a further argument that the TSA is successful because they have prevented a certain number of guns on planes. But the TSA is not keeping guns off of planes merely for the sake of keeping guns off planes. That is where some of us start talking past each other. Were there any tests done pre-911 to see how effective the old private screeners did in detecting guns? But to the point of the thread, I do not recall any hijackings in the U.S. pre-TSA starting from when metal detectors were first installed in the early 1970s until September 11, 2001. Yes, they tragically hit us in the chin on that day, but that scenario, as has been said, will never play out again. There is simply no way that terrorists will breach the cockpit of an aircraft again to use it as a missile. So, I think it reasonable to look back almost twenty years later and ask if these billions of dollars are worth it. Not only the billions of dollars, but flying is just no longer fun anymore. I don’t like having to waste two hours of my life by getting to the airport so damned early. My daughter will never get the experience of seeing her friend off at the gate, or having a beer or coffee with her friend at the gate before her flight. Of course, these things are worth giving up if it means that people will be getting killed, but I am not convinced that is the case. ---
**Author:** ![Lord\_Feldon](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lord_feldon/32/341_2.png) [@Lord\_Feldon](https://boards.straightdope.com/u/Lord_Feldon)\ **Post date:** [January 10, 2019, 1:19pm UTC](https://boards.straightdope.com/t/has-tsa-screening-at-us-airports-stopped-a-single-terroristic-plot-since-its-establishment/827429/58 "2019-01-10T13:19:24Z")
> [@UltraVires](#): > > I don’t like having to waste two hours of my life by getting to the airport so damned early. My daughter will never get the experience of seeing her friend off at the gate, or having a beer or coffee with her friend at the gate before her flight. The lines are so long! And there aren’t enough people in them! ---
**Author:** ![UltraVires](https://avatars.discourse-cdn.com/v4/letter/u/ecccb3/32.png) [@UltraVires](https://boards.straightdope.com/u/UltraVires)\ **Post date:** [January 10, 2019, 1:24pm UTC](https://boards.straightdope.com/t/has-tsa-screening-at-us-airports-stopped-a-single-terroristic-plot-since-its-establishment/827429/59 "2019-01-10T13:24:59Z")
> [@Lord\_Feldon](#): > > The lines are so long! And there aren’t enough people in them! But pre-TSA, you empty your pockets in the little change thing, run your bag through the x ray machine, step through the metal detector and off you go. The lines are not long because of too many people, but because of people having to take off shoes, belt, put laptop in separate bin, listen to some sovereign citizen argue with the TSA agent that the hatchet in his carry on is a tool of his trade and bring up the TSA website to incorrectly argue that it is permitted, etc. ---
**Author:** ![Ravenman](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ravenman/32/2929_2.png) [@Ravenman](https://boards.straightdope.com/u/Ravenman)\ **Post date:** [January 10, 2019, 1:51pm UTC](https://boards.straightdope.com/t/has-tsa-screening-at-us-airports-stopped-a-single-terroristic-plot-since-its-establishment/827429/60 "2019-01-10T13:51:22Z")
> [@UltraVires](#): > > But to the point of the thread, I do not recall any hijackings in the U.S. pre-TSA starting from when metal detectors were first installed in the early 1970s until September 11, 2001. > **[List of aircraft hijackings](https://en.wikipedia.org/wiki/List_of_aircraft_hijackings)** > > The following is a list of notable aircraft hijackings. There were quite a few U.S. hijackings during that period – more than I would have guessed. [Previous page](https://boards.straightdope.com/t/has-tsa-screening-at-us-airports-stopped-a-single-terroristic-plot-since-its-establishment/827429.md?page=2) [Next page](https://boards.straightdope.com/t/has-tsa-screening-at-us-airports-stopped-a-single-terroristic-plot-since-its-establishment/827429.md?page=4)