# What are the purposes of various security screenings? **URL:** \ **Category:** Factual Questions\ **Created:** [October 26, 2022, 9:04pm UTC](https://boards.straightdope.com/t/what-are-the-purposes-of-various-security-screenings/973841 "2022-10-26T21:04:20Z")\ **Posts on this page:** 20\ **Page:** 3
**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:** [October 28, 2022, 5:31pm UTC](https://boards.straightdope.com/t/what-are-the-purposes-of-various-security-screenings/973841/41 "2022-10-28T17:31:51Z")
> [@Saint\_Cad](#): > > We had a family member who had a lock-blade hunting knife that a few months before had gotten lost. What no one knew until the TSA screening was that it had somehow gotten between the lining of her purse and the leather and worked its way to the bottom so no evidence of it other than the x-ray and it was so well hidden it took 2 TSA ten minutes to find it.. Honestly, if you were trying to smuggle a huge-ass knife to do some damage on a plane, it would probably be this way. We were asking ourselves who was going to cancel their vacation to go with her to jail and bail her out because although WE knew it was a mistake, they certainly did not. When they found it they of course confiscated it (and it probably went home with one of them) and then they > > just let her go. Have a nice flight. Okay, so i obviously carry knives around more than i should, but I’ve been caught with knives by TSA a couple of times. And my experience is that they’ve let me check the bag, run back to security, cut in line, and then be quickly screened sans knife. I had the option of throwing away the knife, but they didn’t make me do it. (I whittle, and routinely pack some pocket knives for non-flying vacations. Sometimes they do get stuck somewhere, and i don’t find them for a while. And…i think both times i was caught, it was on the way home. They really aren’t very good at finding knives.) A person carrying a knife is not a real threat. Now that there’s a hard door protecting the pilot, there’s nothing you can do with a knife on a plane that gets you any real benefit, even if you are willing to die. The security mavens were going to drop the ban on small knives, except the public threw a fit, because it was too scary. They keep loosening things around the edges. You can now carry small scissors, and a lot of other knife-like objects on airplanes. Just, God forbid, not something that’s called a “knife” or a “box cutter”. Because that’s too scary. ---
**Author:** ![LurkMeister](https://avatars.discourse-cdn.com/v4/letter/l/3da27b/32.png) [@LurkMeister](https://boards.straightdope.com/u/LurkMeister)\ **Post date:** [October 29, 2022, 9:16pm UTC](https://boards.straightdope.com/t/what-are-the-purposes-of-various-security-screenings/973841/42 "2022-10-29T21:16:25Z")
A few TSA-related stories from my own experience: Once when flying from Chicago to Las Vegas I got to the airport and realized I had left my ID at home. I was able to check my bag curbside on the strength of my ticket, and when I got to Security and explained that I didn’t have my ID I was questioned and searched, then allowed to pass through and board my flight. As soon as I got to my hotel I was able to get someone to overnight my ID to me, so I didn’t have any trouble getting home. TSA was polite and understanding about the whole thing. On several occasions I realized after I had checked my bag that my pocket knife was still in my pocket. I tucked it into my carry-on, fully expecting to lose it during inspection. Each time, the carry-on went through X-ray without any problem. On the other hand - One time my carry-on was pulled for hand inspection, My pocket knife had been put into my checked bag, but apparently something had showed up on the X-ray. After the hand inspection it was put through the machine again, and whatever had caused the alert was still there. The TSA agent said whatever it was looked like a corkscrew, which puzzled me because there’s no reason I would have had a corkscrew in my carry-on. Finally they decided that I was safe to go through. After I got home I completely emptied the bag and couldn’t find anything that could possibly have set off the machine. ---
**Author:** ![Ann\_Hedonia](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ann_hedonia/32/319_2.png) [@Ann\_Hedonia](https://boards.straightdope.com/u/Ann_Hedonia)\ **Post date:** [November 4, 2022, 5:47am UTC](https://boards.straightdope.com/t/what-are-the-purposes-of-various-security-screenings/973841/43 "2022-11-04T05:47:34Z")
> [@LurkMeister](#): > > A few TSA-related stories from my own experience: > > Once when flying from Chicago to Las Vegas I got to the airport and realized I had left my ID at home. I was able to check my bag curbside on the strength of my ticket, and when I got to Security and explained that I didn’t have my ID I was questioned and searched, then allowed to pass through and board my flight. As soon as I got to my hotel I was able to get someone to overnight my ID to me, so I didn’t have any trouble getting home. TSA was polite and understanding about the whole thing. I once lost my ID while on vacation and didn’t realize until the night before I was leaving. I got to the airport early, explained the situation, and showed them all the ID, ( credit cards and the like) that I had with me. They REALLY wanted a photo ID of some sort. I found an old laminated photo ID badge from a construction job I’d worked on about 10 years before, and that did the trick. They only reason I had hung onto that badge was because it was a really good photo….who knew my vanity would pay off years later? My biggest frustration with the situation was that I also had clear full-sized photos on my iPad of my drivers license (front and back) and the main page of my passport. TSA deemed these completely useless, they wouldn’t even look at them. My weirdest story is about grapefruit. I had purchased a single serving plastic container, factory sealed, of course - of grapefruit slices in light syrup in a convenience store in the airport lobby. They were seized by security because it was a container of “liquid”. Not only that, but the initial agent wasn’t sure if it was allowed, her supervisor wasn’t sure either, so I had to hang around security until the supervisor’s supervisor made the determination that my factory-sealed cup of grapefruit slices was too dangerous to be allowed on a plane. They did graciously offer to let me consume them at the checkpoint but I declined. ---
**Author:** ![Francis\_Vaughan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/francis_vaughan/32/3093_2.png) [@Francis\_Vaughan](https://boards.straightdope.com/u/Francis_Vaughan)\ **Post date:** [November 4, 2022, 7:06am UTC](https://boards.straightdope.com/t/what-are-the-purposes-of-various-security-screenings/973841/44 "2022-11-04T07:06:48Z")
Whilst we are exchanging stories. Years ago (before the Arab Spring), I visited Libya for work. I was working in oil and gas at the time and there was a conference there, plus we wanted to talk to the government oil company. Before I went, I mentioned this trip to a friend of mine who is seriously into olive oil. He asked me to get him a bottle of Libyan olive oil. As I left, I had had no luck finding a bottle anywhere I had been (we were very limited in where we went) but once inside the departure lounge and past security, I found a store selling tourist things, and they had bottles of olive oil. Excellent! So I bought a bottle. I then went to the gate. There was another security screening to get onto the plane. They confiscated my bottle of olive oil. To this day I’m sure it went straight back on the shelf in the store. ---
**Author:** ![Mama\_Zappa](https://avatars.discourse-cdn.com/v4/letter/m/71e660/32.png) [@Mama\_Zappa](https://boards.straightdope.com/u/Mama_Zappa)\ **Post date:** [November 4, 2022, 8:29am UTC](https://boards.straightdope.com/t/what-are-the-purposes-of-various-security-screenings/973841/45 "2022-11-04T08:29:46Z")
> [@Dinsdale](#): > > But the rest of the steps? On the way to OHare, they gave me extra attention because I failed to pull a cough drop out of my pants pocket - and I remember once being with my BIL who was almost strip searched over an overlooked antacid tablet. Theater, really. Some of it may be that the TSA people are bored. My first time in a full-body scanner was in 2010 - and first the kleenex in my pockets cause some concern… then I got patted down but only between knees and hips. Sorry, TSA, that cellulite is not going to harm anyone but me! They did save us from 2 weeks travelling around in 115 degree weather with a 16 year old who liked Axe Body Wash (it got confiscated and discarded). On a later trip, my toothpaste was deemed a hazard. I’d tossed it in my bag without thinking - as the trip in question was one decided upon and booked in a major hurry, and I was operating on very little sleep. A friend managed to accidentally smuggle a small knife onto a plane. She forget she had it with her (purse? keychain?) and realized when she got to her destination. Yeah, I feel REAL safe knowing TSA is on the job. Like puzzlegal’s story, she had a friend bring it home (me, actually; we were driving, so we tossed it in our car, and mailed it to her when we got home). > [@Ann\_Hedonia](#): > > the main page of my passport. TSA deemed these completely useless, they wouldn’t even look at them. There are stories of TSA agents not recognizing a US passport card. I couldn’t find a link just now (my Google-fu is weak tonight). Others have failed to recognize that New Mexico is in the US. In theory, one CAN fly without ID, but it’s a lot tougher. > [@TSA site](#): > > In the event you arrive at the airport without valid identification, because it is lost or at home, you may still be allowed to fly. The TSA officer may ask you to complete an identity verification process which includes collecting information such as your name, current address, and other personal information to confirm your identity. If your identity is confirmed, you will be allowed to enter the screening checkpoint. You will be subject to additional screening, to include a patdown and screening of carry-on property. > **[Acceptable Identification at the TSA Checkpoint | Transportation Security...](https://www.tsa.gov/travel/security-screening/identification)** > > Adult passengers 18 and older must show valid identification at the airport checkpoint in order to travel. ---
**Author:** ![kayaker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kayaker/32/441_2.png) [@kayaker](https://boards.straightdope.com/u/kayaker)\ **Post date:** [November 4, 2022, 12:43pm UTC](https://boards.straightdope.com/t/what-are-the-purposes-of-various-security-screenings/973841/46 "2022-11-04T12:43:13Z")
> [@Mama\_Zappa](#): > > A friend managed to accidentally smuggle a small knife onto a plane. I had a tiny souvenir keychain knife taken from me by security when I entered a courthouse. It was a pitiful little knife. As the guard did paperwork and locked my knife in a security box, I mentioned that I could cause more harm with my pen. The guard put his hand on his gun and asked for my pen, which he examined, then returned. ---
**Author:** ![Dinsdale](https://avatars.discourse-cdn.com/v4/letter/d/97f17d/32.png) [@Dinsdale](https://boards.straightdope.com/u/Dinsdale)\ **Post date:** [November 4, 2022, 12:56pm UTC](https://boards.straightdope.com/t/what-are-the-purposes-of-various-security-screenings/973841/47 "2022-11-04T12:56:23Z")
> [@kayaker](#): > > The guard put his hand on his gun and asked for my pen, which he examined, then returned. Ha! I can clearly see that in my mind’s eye! What a sorry state of affairs. I am in and out of federal buildings al the time such that I am a perfect sheep in such situations. It is just that every once in a while in a situation such as the Empire State Building, that such ridiculous interactions catch my attention. As I’ve said, if they just stated it clearly, I’d pretty much strip down to my skivvies. Hey - you got a few acres of wilderness in your neighborhood on which I can be a hermit? ---
**Author:** ![Francis\_Vaughan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/francis_vaughan/32/3093_2.png) [@Francis\_Vaughan](https://boards.straightdope.com/u/Francis_Vaughan)\ **Post date:** [November 4, 2022, 1:22pm UTC](https://boards.straightdope.com/t/what-are-the-purposes-of-various-security-screenings/973841/48 "2022-11-04T13:22:06Z")
> [@kayaker](#): > > I mentioned that I could cause more harm with my pen. I guess my sword isn’t a problem then. ---
**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:** [November 4, 2022, 1:37pm UTC](https://boards.straightdope.com/t/what-are-the-purposes-of-various-security-screenings/973841/49 "2022-11-04T13:37:45Z")
I had a tiny jeweled knife on my keychain when i went to a campaign event for John Kerry. The guard wouldn’t let me in with it. I pointed out it would be very hard to hurt anyone with the ½" blade. He agreed, but said he could lose his job if he let me in. That seemed like a compelling argument, so i went to the hotel lobby and asked them to hold it for me, and trudged back through the security line. ---
**Author:** ![Dinsdale](https://avatars.discourse-cdn.com/v4/letter/d/97f17d/32.png) [@Dinsdale](https://boards.straightdope.com/u/Dinsdale)\ **Post date:** [November 4, 2022, 1:53pm UTC](https://boards.straightdope.com/t/what-are-the-purposes-of-various-security-screenings/973841/50 "2022-11-04T13:53:59Z")
I remember speaking to some courthouse guards several years back. They told me how often folk walked through the metal detectors with large knives and guns, despite clear signs on the doors, and the obvious presence of security measures. Absolutely nothing prevented these yahoos from turning around and leaving their weapon in their car - or even under some bushes. But instead, they strolled through the magnetometer as tho it wouldn’t match them. Just yesterday, our security guard wanded an individual with a decent sized (approx 3-4" blade) pocket knife… ---
**Author:** ![doreen](https://avatars.discourse-cdn.com/v4/letter/d/858c86/32.png) [@doreen](https://boards.straightdope.com/u/doreen)\ **Post date:** [November 4, 2022, 2:05pm UTC](https://boards.straightdope.com/t/what-are-the-purposes-of-various-security-screenings/973841/51 "2022-11-04T14:05:08Z")
I could see forgetting you have a pocket knife on your keychain or something like that. But I can’t see forgetting that you have a gun with you. ---
**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:** [November 4, 2022, 2:06pm UTC](https://boards.straightdope.com/t/what-are-the-purposes-of-various-security-screenings/973841/52 "2022-11-04T14:06:42Z")
If it’s something you always carry, you just don’t think about it much. ---
**Author:** ![Llama\_Llogophile](https://avatars.discourse-cdn.com/v4/letter/l/49beb7/32.png) [@Llama\_Llogophile](https://boards.straightdope.com/u/Llama_Llogophile)\ **Post date:** [November 4, 2022, 2:09pm UTC](https://boards.straightdope.com/t/what-are-the-purposes-of-various-security-screenings/973841/53 "2022-11-04T14:09:06Z")
> [@Doreen](#): > > I could see forgetting you have a pocket knife on your keychain or something like that. But I can’t see forgetting that you have a gun with you. I would think so too, but I actually know someone who mistakenly went through security at his work place with a pistol in a bag. He completely forgot it was there, it was an honest mistake. After apologizing, he went and locked it in his car, then went in to work. Still got fired for it. But an honest mistake nonetheless. ---
**Author:** ![kayaker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kayaker/32/441_2.png) [@kayaker](https://boards.straightdope.com/u/kayaker)\ **Post date:** [November 4, 2022, 2:10pm UTC](https://boards.straightdope.com/t/what-are-the-purposes-of-various-security-screenings/973841/54 "2022-11-04T14:10:09Z")
> [@puzzlegal](#): > > If it’s something you always carry, you just don’t think about it much My every day carry is a Kershaw assisted opening 4 inch blade knife. To me it is a tool that comes in handy every day or two, but I’ve had people freak out over my “switchblade” (it isn’t). ---
**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:** [November 4, 2022, 2:17pm UTC](https://boards.straightdope.com/t/what-are-the-purposes-of-various-security-screenings/973841/55 "2022-11-04T14:17:25Z")
I’m not sure what the definition of a switchblade is. ---
**Author:** ![hajario](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hajario/32/171_2.png) [@hajario](https://boards.straightdope.com/u/hajario)\ **Post date:** [November 4, 2022, 2:24pm UTC](https://boards.straightdope.com/t/what-are-the-purposes-of-various-security-screenings/973841/56 "2022-11-04T14:24:13Z")
It’s a type of folding knife that automatically opens with a spring mechanism. ---
**Author:** ![kayaker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kayaker/32/441_2.png) [@kayaker](https://boards.straightdope.com/u/kayaker)\ **Post date:** [November 4, 2022, 2:27pm UTC](https://boards.straightdope.com/t/what-are-the-purposes-of-various-security-screenings/973841/57 "2022-11-04T14:27:08Z")
As I understand it, A switchblade knife is one where on the push of a button, the blade “shoots” straight out. With an assisted opening knife blade a lever or stud is used to “swing” the blade open. Assisted opening knife: [![](https://img.youtube.com/vi/o8G8JcU-Mdc/maxresdefault.jpg "Inside Kershaw SpeedSafe assisted opening") ](https://www.youtube.com/watch?v=o8G8JcU-Mdc) Switchblades: [![](https://img.youtube.com/vi/yL_gA8GxJvc/hqdefault.jpg "What Is a Switchblade? | Knives") ](https://www.youtube.com/watch?v=yL_gA8GxJvc) > [@hajario](#): > > It’s a type of folding knife that automatically opens with a spring mechanism Not necessarily “folding”, in fact in the more common switchblades the blade does not fold. ---
**Author:** ![HMS\_Irruncible](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hms_irruncible/32/7394_2.png) [@HMS\_Irruncible](https://boards.straightdope.com/u/HMS_Irruncible)\ **Post date:** [November 4, 2022, 2:31pm UTC](https://boards.straightdope.com/t/what-are-the-purposes-of-various-security-screenings/973841/58 "2022-11-04T14:31:11Z")
Nobody wants the one to say “Let’s have slightly less security” and then have something bad happen on their watch. Individuals take calculated risks all the time, but they will mercilessly punish any authority or institution who does it on their behalf. ---
**Author:** ![hajario](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hajario/32/171_2.png) [@hajario](https://boards.straightdope.com/u/hajario)\ **Post date:** [November 4, 2022, 2:39pm UTC](https://boards.straightdope.com/t/what-are-the-purposes-of-various-security-screenings/973841/59 "2022-11-04T14:39:41Z")
> [@kayaker](#): > > Not necessarily “folding”, in fact in the more common switchblades the blade does not fold. I’m no expert and I’ll defer to you. Back in the day we called the ones that flipped open switchblades and the ones that shot open stilettos. ---
**Author:** ![kayaker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kayaker/32/441_2.png) [@kayaker](https://boards.straightdope.com/u/kayaker)\ **Post date:** [November 4, 2022, 2:50pm UTC](https://boards.straightdope.com/t/what-are-the-purposes-of-various-security-screenings/973841/60 "2022-11-04T14:50:14Z")
I’m not an expert, but the big knife manufacturers are careful to stick to precise definitions due to laws restricting sale/ownership of certain types of knives. Stiletto was a term used by Italian switchblade manufacturers for their knives that shot straight forward. Switchblades require no force to open, other than pressing a button. It gets pretty complicated: > **[Assisted-opening knife](https://en.wikipedia.org/wiki/Assisted-opening_knife)** > > An assisted-opening knife is a type of folding knife which uses an internal mechanism to finish the opening of the blade once the user has partially opened it using a flipper or thumbstud attached to the blade. > When the knife is in the closed position, the blade is held in place by means of torsion springs and an additional blade lock (optional). As the user applies manual pressure to the thumbstud to open the knife, a mechanism such as a torsion spring moves along a track in the liner and rapid... [Previous page](https://boards.straightdope.com/t/what-are-the-purposes-of-various-security-screenings/973841.md?page=2) [Next page](https://boards.straightdope.com/t/what-are-the-purposes-of-various-security-screenings/973841.md?page=4)