A few weeks ago there was a conversation [1] regarding the utility of signals like this, with a common opinion that they are useless. I'm very happy to see that it worked!
I think what confused me, and probably most other people is that they didn't realize that domestic violence situations can often turn into kidnapping / hostage situations, which is what the hand signal is actually designed for, and what it was used for in this case as well.
> kidnapping / hostage situations, which is what the hand signal is actually designed for
The description doesn't say that at all; it only discusses domestic violence and, if you see the signal, 'check in' with the person signaling. Presumably, if they were talking about kidnapping or hostage situations, they would suggest calling the police.
Actually learning sign language (the alphabet) is very beneficial in general, also when you are hearing. The ability to talk over large distances or when its very crowded. Takes a few days to learn at most.
I was thinking of learning sign language, but what's stopping me is the impression that it varies across countries or regions (one of the hints is that ASL stands for "American Sign Language", I think we have something else here in Europe). I haven't put much research into this yet, though, so maybe I am mistaken.
And the fact that this happens means next time it will work better, since probably 100 times more people know the signal now. (I've heard it described on the radio, and it is getting repeated everywhere on the net)
I think the bigger news is that the common opinion is that TikTok is useless, and this provides a rare counterexample. :)
Secrets can be kept in the open for long periods of time if the bad actors remain ignorant. Look how long thieves were breaking into Teslas without realizing they were being recorded by the built-in cameras, even though examples of this happening were common.
Bad actors know about 911, and folks are still sometimes able to call it to get help. Even if well known, this would be the worst case scenario. To be honest, though, it won't be so bad: There are lots of times that someone might be able to secretly make a hand signal - and those are the same times you can't exactly tie someone's hands together. (you can just take a phone away)
Wouldn't that mean criminals know the signal too? This might be one thing that was better left on tiktok, where presumably the people who need it the most are
I'm happy that it worked as well, but then there's this:
> Police say the teenager told investigators that she traveled with the man through North Carolina, Tennessee, Kentucky and Ohio. Authorities allege she had been attempting to get motorists’ attention to call 911.
What percentage of the population would have any idea what that hand signal (or any hand signal) means? Other than extremely common things like the middle finger, of course.
That was prisoners in North Korea at a time of much less intercultural contact. It might still work -- in North Korea -- today, or it might not. It could not possibly work anywhere else.
Indeed, times have changed. The whole world consumes American media. Despite this, my brother and I were able to have coded conversations in a European hostel (where everybody spoke English fluently) using shared anecdotes (Shaka, when the walls fell). We weren't in duress, but not all is lost for people who are.
It's weird because maybe a small percentage of people know the signal, and if the signal became Too Popular then it would lose effectiveness or otherwise be recognized by those who would cause harm
Your comment reminds me of a video clip I saw where someone dialed 911 and proceeded to "order a pizza," thus giving them her address. She got lucky and the dispatcher was fairly quick to figure it out and didn't hang up on her.
I suppose it's not pure luck at all. Here in Brazil dispatchers are trained to cope with callers that appear to be trying to sneak an address in a seemly unusual call.
Maybe it did? What if she showed 50 people the symbol across 2 states before someone recognized it? What if she just mouthed "help me" to people who saw her, which is how it was done in the good ol days.
> A few weeks ago there was a conversation [1] regarding the utility of signals like this, with a common opinion that they are useless.
Unfortunately, typical for HN - a bit odd for a community built around innovative startups. Look at the top comment for almost every discussion, a smarter-than-thou takedown of whatever the OP says. I wish the mods would automatically move that comment to the bottom.
We do whenever we see it. You can always let us know at hn@ycombinator.com if there's a particularly bad one.
Unfortunately, this comment here, and the fact that it was pinned to the top of the subthread, is sort of a variant of the same thing. I'll mark it off topic now.
It's okay to be critical of proposed ideas. The problem with hand held signals such as this is that they're self-defeating.
To be effective they must be widely understood and conspicuous. If they are well understood and conspicuous, then the attacker will punish the victim for attempting to make them.
Attackers will surely see articles like this and will prevent victims from putting their hands anywhere near the glass in future.
Calling 911 by that logic is self defeating because it's easily recognizable and can easily be preventable, but it's not, because these things aren't about being fool-proof, but giving people a means to communicate if the opportunity arises to do so. A silent hand gesture is perfect, can be easily made when someone turns their back, or is distracted and if recognized, can potentially save your life. But yes, it depends on IF the opportunity arises to do so, even if the attacker knows the hand signal. And a silent hand signal is incredibly easy to pull off in a situation like what occurred to this poor girl.
Yes, the first thing a kidnapper will do is remove your phone from you because they're aware it can be used to call 911. So 911 is self-defeating in certain situations because attackers are aware of it and will target people in such a way as to avoid 911 being called. However, it still has utility because there are a range of situations where attackers take some time to subdue their victims (such as a home invasion) or in cases where there is a witness unseen by the attacker.
These hand signals only make sense in cases where the attacker already has physical (though not mental) control over the victim and the crime is not immediately obvious to witnesses.
I think this case would actually be one of the easiest for the attacker to prevent with prior knowledge of the hand signal. Most people hardly ever look at the occupants of passing cars and only subset of them would have the knowledge and presence of mind to interpret the signal and not dismiss it anyway. So, a victim would have to have their fist pressed up against the glass for an extended period of time. The attacker, sitting right next to the victim, would catch that in their peripheral vision pretty quickly.
Yes, nobody is saying it's completely impervious to being prevented. It's a discrete way of alerting people to you being in danger, I don't know why you think it's a bad thing when it has literally been proven to be effective and potentially saved a young womans life. I do not understand the hostility to the idea.
I don't think it's a bad thing persay, I just think we should not overplay the effectiveness of it.
I also take offence to OP's suggestion that reasoned arguments critiquing the practice be 'automatically' moved to the bottom of the thread. As though such arguments can never be made in good faith.
Yes, there are clearly some situations where it has worked in the past, which is a good thing. But, we shouldn't start a massive public awareness campaign and create courses on it in schools because its aggregate effect would likely be small relative to other possible interventions.
Now, you may argue that you never suggested such a thing and that'd be a fair retort. However, then what is the potential aggregate impact such a programme? I'd argue very small for the reasons I've outlined previously. So, it be better to raise awareness and lobby for interventions to kidnapping and human trafficking with proven efficacy.
The hand signal just needs to be silent, so it can be flashed secretly at strangers. In this case, it worked. The teenager was able to flash the signal at a driver without alerting her captor
That might work if the driver happens to be blind. But as I said, an attacker with knowledge of the use of hand signals to seek help would be alert to their passenger holding their hand up to window. So, they'd either restrain their passenger or threaten them to keep their hands away from the window.
It worked this time because we're in a local optimum of sorts where enough community members understand the signals to help and enough attackers don't know about the signal to prevent it from being made. However, as community consciousness of these signals grows (through articles such as this) attackers will get wise to the practice. Hence, they're self-defeating.
It could work even if the kidnapper knew it in cases like this:
* kidnapper distracted by other things
* kidnapper distracted by having been on the road long enough to be spending all their energy on "not falling asleep" and "paying attention to the road ahead"
* victim in back seat, partially hidden
* kidnapper has temporarily left victim alone in a place they feel confident flight is unlikely
If it starts to become too popular then once stories start spreading of victims who managed to escape despite their kidnapper noticing them using this sign, then new signs will be suggested and circulated. Asking a bartender/waitress if they can make a particular (nonexistant) drink. Blinking in a certain cadence. Crossing your arms and tapping your upper arm five times. Whatever. Language evolves.
I've been in the women's bathroom in bars and seen signs posted out of view from outside that say "if you need help escaping from the person you are with, say this innocuous but specific phrase to the staff". This was long before TikTok existed, and maybe before this gesture existed - I dunno, maybe I just never got shown it.
The problem with all these sertipious signals is that there would essentially be so many of them that all kind of innocuous behaviour could be misinterpreted and people would become unsure and it'd all come full circle. It'd end up in comedic farce.
With regards to the bar examples, they may work in a constrained context where the victim is familiar with the venue. They wouldn't work in the case of victim being transported around under the control of their attacker.
The bar example works absolutely fine for someone unfamiliar with the venue: you go to the bathroom as you normally would, and you see a sign in there that says "hey if you're in trouble do this and we will help you out", then you come back out and you do that.
There is a sweet spot between "enough people know what this signal means for it to be worth using" and "so many people know this that my adversary knows it too". The signal this kid used may be about to cross the upper threshold soon, but it worked for her.
Surreptitious and obscured communication channels have been being created and getting detected for most of human history. Look at the continuing cycle of teenage subcultures creating slang to perform the dual function of marking a member of the group and obscuring one's plans from one's parents; look at Thieves' Cant; look at histories and manuals of spycraft. And those spycraft books will probably have suggestions on what to do if you're in a situation where signals just aren't viable, too; signals are one tool.
It seems like you're approaching this like a spherical cow, instead of a real world problem. It's easier to discreetly hand signal than to say something.
There is nothing wrong with simplifying a problem to get at its essence, but yes it is important to accept real-life is messy.
I'm sure in a restricted set of circumstance this may help people (as it did in this story), but I sincerely doubt it'd lead to a material increase in kidnapped people being liberated.
It'd certainly be less effective than other interventions such as cracking down on people trafficking networks or poverty reduction programmes.
The expressiveness of hand gestures (in general) is quite limited and any gesture used for covert communication must make a tradeoff between conspicuousness to the public and conspicuousness to the attacker. This limitation restricts the situations in which they can be made and results in gestures that could be easily dismissed or otherwise misunderstood and thus limit their utility.
I can't believe this needs to be pointed out, but it's not an either-or proposal. We can have signals such as this one, as well as efforts to curtail human trafficking.
> The expressiveness of hand gestures (in general) is quite limited
Clearly you've not met many sign language speakers. Or Italians.
This is a perfectly cromulent covert hand gesture. It has high coding entropy - I've literally never once seen someone make this gesture (outside of videos demonstrating it). Fingerspelling is not remotely similar since it's a sequence of codes in rapid succession.
It's not like the victim is losing something if the signal is widely known. It raises the stakes for the attacker who now also has to constantly monitor for hidden signals.
Yes, the attacker can strip-search the victim for smartphones and GPS trackers and then tie them down in the trunk, but the game is getting harder for kidnappers.
The symbol appears (to me) to be deliberately designed to be easy to disguise with a wave or other subtle hand gesture, particularly on some sort of video call. It's very obvious from the front, but not very obvious from other perspectives. It's this information differential that makes it effective.
If you are at the point where you cannot even get your hands near where other people can see them, your signal bandwidth to the outside world is likely already severely curtailed. As in, you are probably locked in a basement. I don't think this is meant to address that severe of a human trafficking/abuse situation.
The video in the article has an example where it can be effective: as a silent non verbal signal. Sure, writing it may be more effective but if for some reason you can’t, then a signal may be helpful.
I don't think this signal becomes useless the moment an attacker knows about it. It's one thing to prevent your victim from speaking to anyone unattended, but it's hard to imagine there never being a moment for them to make a quick hand gesture to the outside world. At some point an attacker has to take their eyes off their victim even if for just a moment.
It's true that attackers can take precautions against this, but that also makes their attack harder to carry out.
That said, when it's generational you get interesting and good effects -- a hand signal the young people know might be enough to save a young person from an old person abducting them.
I definitely see what you're referring to happen a lot. Ironically, one thing I also enjoy about HN is reading a questionable article and seeing the top comment be a well thought out take down from someone who seems like a real expert. But it's true the top comment regularly seems to be a (sometimes egregiously wrong) takedown or downplaying.
I see the zealotry surrounding rationalism in this space but was always puzzled by it.
Rationality is achieved when one merely makes rational arguments following some axiom or assumption. But it says nothing about the reasonableness of the axiom or assumption per se. It would seem that some folks employ faulty assumptions in supposedly rational discussions, assuming that they are winning the debate (whether it is a debate or not) without considering their blind spots.
I noticed it depends a lot on the actual expertise of the commenter. Some are really high end, and comments follow to be interested. If it’s not, you see counterpoints arise fairly quickly.
Please don't, these comments are most valuable. In fact when something is relevant for me I wait for some time and revisit the comments. The top comment is often indeed the opposite view, and as such, very valuable and it allows you to make up your own mind. The truth (or I should say "a considerate opinion") is often in the middle of OP and the top comment, I find.
"In the studio today we have someone who has been studying this topic at a reputable institution for decades. And to argue a different side we have someone who only learned about this topic ten minutes ago but nonetheless can be relied upon to have strong contrary opinions, no matter the subject."
Of course the reputable person could be wrong but listening to the guy spouting BS is not going to help discern the truth, which is almost certainly not anywhere in whatever "middle" was conjured up by the BS.
Yeah, that indeed, so... see how everything fits in your world-view and think about both stances and form an opinion keeping an open mind and acknowledge that you could still be wrong...
Then, you could test that opinion by writing a respectful comment to the top comment. :)
Your top voted reply to the first comment shows the same same issue.
It would be really great if HN provided multiple different moderation systems, so everyone could select a moderation algorithm that suited them better.
I actually enjoy them, as long as they are civil and technically correct. They are right to point out that the signal had nothing to do with the rescue, its a fair point.
I treat those comments as reality check that lets me question my own stance and views. Afterall we all have different opinions, and mine might not be right.
I don't! Why should the first response be uncritical praise? If it were to always be one or the other, I'm pretty sure I'd prefer critical. That'd better mirror real-world unmanaged debate/didagreement (if that's a goal) too.
I even hesitated clicking on the comment section as it was totally clear this was going to be dominated by contrarian for contrarian's sake comments, Reddit style.
It certainly helps for some deep technical articles, but when it comes to broader topics, HN has become grumpy and old.
I used to be like that and find that re-conditioning myself is really hard. Agreeing to something while acknowledging its flaws seems so bland if you can write a scathing take-down instead...
As an alternative perspective: Writing a 'scathing take-down' is lazy BS; you don't have to know anything or even do anything. It adds nothing to the world.
To write something constructive takes thought and creativity (as in, to 'create' something).
("Agreeing to something while acknowledging its flaws" isn't the alternative.)
But it is also satisfying having read the article want to give your hot take on the matter and the top comment nails it already. Saved me at least a half hour.
It's extremely easy to arrive at false generalizations by considering only the subset of the data that makes the strongest impression on you. On the internet, including HN, what makes the strongest impression are all the things that aggravate and activate and rub us the wrong way. The positive and innocuous portions of the data set, of which there are plenty, get left out of this generalization. You would arrive at opposite conclusions with different data points.
Supercilious putdowns of the rest of the community are notoriously even easier and more tempting than other forms of this cognitive bias, because they gratify other motivations too. They predictably lead to lame and tedious discussion, which is why we have that guideline. Here are some congruent things to do instead:
(1) leave the community if you feel it's so bad;
(2) post substantive contributions that make things less bad;
(3) find how you yourself are doing the thing you complain about, and change that aspect.
Would you please review the site guidelines (https://news.ycombinator.com/newsguidelines.html) and stop breaking them? I'm unfortunately seeing a lot of that in your recent commenting history.
I'm sorry. I didn't mean to imply that you should leave, and should not have been provocative by including that on the list. In that way you're quite right.
FWIW, the option I would personally like you to choose (not that you should particularly care what I want) is #2. That is, I would like you stay, and also to follow the site guidelines. The problem is that your comments have been frequently and seriously breaking them, and we need you to fix that if you want to keep commenting here (which I hope you will). We've already had to ask you to fix this numerous times, and to judge by your commenting history, it's gotten worse recently. At the same time, your reply here made me realize that I overreacted to that, which I shouldn't have. I'm also mindful that it wasn't always this way, and you've posted good things in the past.
As for "how people generally perceive HN", it's not that we/I don't care about that (we definitely do), but you have to understand that we're inundated with all kinds of generally-perceive-HNs, and these "general" perceptions are all over the place and profoundly contradictory. In fact, they're a statistical distribution that covers the entire spectrum. It's difficult to extract much signal from that—especially because people tend to express their personal feelings and complaints and views and experiences in the form of strong general claims. That doesn't mean we're not open to criticism and questions—it just means that criticisms and questions are best communicated in the form of specific points with specific links, and without a lot of the rhetoric that people (I'm speaking generally, not about you) often pour into these things.
Relatedly, would you please review the site guidelines (https://news.ycombinator.com/newsguidelines.html) and stop breaking them? I'm unfortunately seeing a lot of that in your recent commenting history.
When I read the original post story I simultaneously thought ‘great’ and upon looking it up ‘that is far too generic a motion with the hand for a signal’.
You've never made a fist "wrong" for punching? Lot's of people have done this when "pretend" boxing with friends. I do it when trying to convey I'm definitely joking about "putting up dukes" in an overly comedic way.
The signal is showing your open palm with the thumb tucked and then closing into a fist, not just the fist on its own. It would be a very weird motion to do unintentionally.
This particular signal was also created during Covid lockdowns and was intended to be something you do to a camera, because you don't have any opportunity to see people in person and ask for help. So you raise your palm towards the camera and then close it into a fist.
When your hand is stiff the basic motion is fully stretching your fingers and then closing your hand over your thumb, repeating a few times. Pretending this is some obscure combination of gestures is just disingenuous.
yes, thanks. i understand the signal. however, if you've ever made a "wrong" fist, you've made this signal. you may not have done it while pointed at a camera or out the window of a moving car, you people have probably gone through the motions of making this signal more times than they think.
you could make this signal with your hand down by your side while being "walked" to a location while in public. it would be much less noticable by the one doing the taking than trying to get people to do it in an "upright" position.
Yeah, fair enough. Again it wasn't really intended to be used in public or to mean "I am in immediate danger, call 911 now", although obviously it worked out well for that purpose in this case. The idea was that if you see a friend do it in a video call then you make an effort to reach out privately and ask if they need help or someone to talk to, and only with further confirmation do you call the police or find them a shelter or something. If they didn't mean to do it, no harm done.
I think you're right that this hand signal is not ideal for "I am currently being kidnapped by the person right next to me", despite this success story.
That's a great way to pop your thumb out of your socket, or sprain it. Yeah okay you'd have to actually make contact with your first, but this is like the first thing they teach you in any kind of martial art / pugilism / punching bag work.
Agreed, I think signs like this are a way of pushing someone's thought from "I wonder if they are ok?" to "They need help." In essence, it makes a situation actionable by an outsider.
It's obscured in this article, but the guy that called the police have said in interviews that he didn't understand the hand sign nor understood it as a hand sign. He reacted because she looked distressed. Empathy and attentiveness saved the day, not some 'tiktok' trick.
Hm, thanks for your input, but that doesn't make such a good headline. "Aware citizen calls police when seeing stressed out teenager"... I don't think that is catchy enough. (/s)
But then it is not because of bad journalism but because of bad word by the police department itself[0]:
"The complainant was behind the vehicle and noticed a female passenger in the vehicle making hand gestures that are known on.the social media platform "Tik Tok" to represent violence at home – I need help – domestic violence."
It is in part because of bad journalism too. Journalists are supposed to to compare multiple sources, and reconcile them to represent the reality as much as possible.
But hey, this is Guardian, so why not go with the clickbaity title and ride the gimmicky TikTok trends?
The collective obsession with TikTok is very strange and cult-like.
This event has nothing to do with TikTok. Hand signals are not new and any medium of communication can be used to propagate their meaning. TikTok is certainly not the only medium by which this particular hand signal has propagated, and might not be the most significant force behind its adoption.
Why was TikTok mentioned so many times? Just to draw clicks on the headline?
TikTok is going through its "honeymoon" period of positive press coverage. ("TikTok saves lives!") Glowing coverage of Google and Apple was like this in the early 2000s. Give it 10 years or so when the pendulum will swing the other way, and you'll be wondering why all the coverage of TikTok is so negative.
It wasnt that long ago that almost all press coverage of TikTok was negative. As it was pointing to China using it to "hack" our mobile phones and steal our data through the intrusive permissions it supposedly uses.
Given that the press didn't do much to sway people's opinions its now being reported on based on the content it provides rather than the platform itself.
Can't say for sure, but I'm guessing the police included that because either the 911 caller or victim (or both) said they learned the gesture from TikTok.
> and might not be the most significant force behind its adoption.
You say that, but if you where using tiktok you’d be one of the roughly billion people who didn’t know about the signal a month ago but then recently learned about it. Trust me, Tiktok was the absolutely major force behind this knowledge becoming widespread, and it’s perfectly reasonable that it’s mentioned. Just like Gangnam style coverage mentioned YouTube. It’s not about clicks or some infatuation with the platforms, it’s just objectively the case that these major platforms have an extreme reach and that’s worth including in your coverage. Especially since many readers like yourself don’t understand just how influential the platform has become, because they haven’t known about it for more than a year or so.
It's also trending on imgur. Since it's not the same user base as HN, and they usually don't trend on the same things at all, I always assume it's a PR compaign when it happens.
So my theory is tik tok is paying some company for that buzz.
Didn't realize this was a thing, cool that it worked.
As a loosely related note, there has been problems in the past where people come up with meanings for hand gestures without knowing the signed language of the region they are in, which leads to people misunderstanding something a person is signing as something completely different. Although probably not a problem in this case, just something to consider if you ever are so inclined to make a manual language.
If anyone was curious in ASL this is basically "B -> M", not that that was on purpose, just a different way this could be interpreted.
> Does the Signal for Help stand for something in a sign language?
> The Signal For Help is not meant to refer to any words, letters, or ideas in American Sign Language (ASL) or other sign languages. It is designed as a single hand motion someone can make during a video call to silently communicate they need support. Deaf community members were consulted on the Signal for Help prior to the launch of the campaign to check in about using this hand gesture.
I sometimes do a gesture similar to this one as a habit for cracking my (thumb) knuckles single-handed. Not as an intentional sign first tucking the thumb in the palm, and then traping it in, but rather as a single motion. I wonder if it could be mistaken for this gesture.
I don't do it rapdily, and it's a single-handed motion, so not the usual "cracking your knuckles" movement/gesture. I do wonder because it could look similar, though I don't specifically direct it so that it'll be palm-to-viewer, as the guides for this gesture tell you to do.
Letter signing is not typical in ASL and in any event BM is not a common letter sequence in English. I would also think that if I made eye contact with someone who signed BM to me, I would have to assume it was this signal or else they were being awfully rude https://en.wiktionary.org/wiki/BM#English
Really? I'm not deaf, but I did take 3 semesters of ASL, and knew a lot of deaf people. In my experience, fingerspelling is incredibly common.
It isn't that people spell everything, but is very common to spell a very specific word, especially for something technical, that one of your following signs will represent. You might spell "Macbook M1", and then use the sign for computer in the rest of the conversation.
I've also found that many people that weren't born deaf, but went deaf later, or that had hearing parents that didn't really help them, often don't know ASL well. It was common for someone to not recognize a sign and the other person would spell out what it was.
A funny oddity about spelling and the deaf. You might (at least I did) think that since they spell things out far more often than we do in spoken English that they'd know how to spell well. That is generally not the case unless the person was raised by hearing people.
I knew a couple where the husband was CODA (child of a deaf adult, both parents) but could hear/speak, and the wife was deaf but was raised by hearing parents. She actually could spell well, but he couldn't, and that was very atypical.
Yes, just like with hearing individuals, not everyone can spell well.
Often times, just like when reading, one may not notice every single letter in a given word, but with the sequence of letters, autocorrect, and context, the meaning is usually clear.
Yes, as mentioned elsewhere, finger-spelling is common when introducing a new person/entity/concept into the conversation.
Regarding the person's expressions, it's common in ASL to employ very dramatic facial expressions to assist and augment the signs themselves to help the "listener" arrive at the correct understanding and feeling.
This would only be possible with a syllable break as in something like fub/moore. Even then, I can't think of a name, or a word, or a common collocation, that features it. Syllables ending in /b/ aren't so common, though they're possible.
Also "entombment", "webmaster", and variations of them. But not many; /usr/share/dict/words on my system lists only 45, many of which are minor variations of each other.
Well, I had shifted into pronunciation (mostly because in writing the concept of a "syllable" doesn't exist), but in the larger context, yes, that's fair.
As the signal is shared and becomes known by the public, there is a risk that an abuser might learn about it. People in abusive situations are also often closely monitored by the person harming them, and they may not always feel safe enough to use the signal.
There is no one-size-fits-all solution for everyone facing abuse. Everyone faces their own unique circumstance. The Signal for Help is one tool some people may be able to use, some of the time, to indicate they need help without leaving a digital trace.
It is important that people reach out for support if and when they feel ready, and they should do it in the ways that feel safest for them. People supporting them should be ready to help without judgement, and they should follow the lead of the person who needs help.
can the 'tiktok scenius' react in real time and just instantly spread a new signal for the next person, don't underestimate how powerful that network is, has the highest quality interaction I have witnessed. more jokes than HN too
> My worry would be that as the signal becomes well known abusers will learn it
I'm so glad that the signal worked in this case, but you're absolutely correct: the problem with clandestine signals like this is that they need to be somewhat widely known to be effective, but if they become too widely known they become ineffective and even dangerous (since the bad actor would likely know the signal and intent).
I've heard stories about prevented tragedies via "code word" drink orders at bars -- maybe that tactic could be more widely applied (bars, restaurants, hotels, gas stations, etc.)
Being able to be made surreptitiously can be enough though. Nothing's foolproof, but if an abuser is trying to over-manage someone's communications or hand gestures, that itself is a give away for people to pay more attention.
Looks like a kidnapping situation, why does it have to do anything with domestic violence?
The main problem with domestic violence, and why it's an unsolvable issue, is that the victim does not want to leave (probably because of sunk costs or similar). If someone is prevented from leaving, it's kidnapping.
What's the origin of this signal then? It starts off making it sound like some sort if TikTok craze/in-joke, but then the Louisiana police & The Guardian seem to be bulleting explainers on how to use it as a sort of public awareness.
'If you take the time to' not assume the worst in people, you might think I just missed it (or even that the article was updated!) - reading again I see it is 'believed to have been' introduced by the Canadian Women's Foundation. Not mentioned until the penultimate paragraph, after having described it as 'known on TikTok', and sharing the police's awareness tweet on it.
I was partly confused on first reading because having misread the title I thought the signal was made and recognised on a TikTok video. Whereas actually - especially since it's a more widely known (apparently) signal, introduced by the Canadian Women's Foundation - this story has nothing to do with TikTok or social media whatsoever.
[1] https://news.ycombinator.com/item?id=28977870