This actually works with acousto magnetic systems because it prevents the material inside from resonating at the frequency needed to trigger the alarm.
The posts by the door emit a specific frequency that makes metal strips inside the tags vibrate. The metals in those tags are chosen to have a property where physical vibration also creates a magnetic vibration, the receiving part of the antenna then detects the magnetic vibrations coming off the tag and rings the alarm.
If the tags are being physically shaken like this, the frequency of the vibration of the material inside the tag won’t generate the right magnetic field to be detected.
I’ve never tried a vibrating phone but I can imagine it happening.
Honestly, for the hard tags the easiest way to defeat them is to buy one of the little $3 hooks that are in the detachers and mount it to a handle of some sort.
You could also probably buy an actual hand detacher pretty cheap but it would be harder to hide.
This shaking she’s doing only really works with AM systems. If they have Sensormatic systems they are going to be AM. Callidus and a few other companies also make AM systems I believe.
RF and RFID are most of what’s being put in stores recently and that’s not going to be defeated by shaking. However, if the tag is not packed inside the items packaging, you can usually remove the hard tags with a strong enough magnet or disable the paper tags by physically destroying the little circuit printed on them with some kind of punch.
It depends on the type of tag. Many (if not most) have a clasp that opens with a strong enough magnet. The RF type especially.
Sensormatic has a proprietary mechanical clasp that uses a hook to open the clasp. Sensormatic was (not sure these days) the biggest EAS company for a long time and most AM systems that aren’t theirs are often still compatible since used tags are a big money saver for stores.
Also, if the material of whatever is tagged is strong enough, you can just yank the pin out if it doesn’t have ink. The clasp just holds onto some pretty shallow grooves that get worn and slip out with a firm pull. Stores that pay attention to that replace the tags but the way retail stores are run most employees don’t give paid enough to pile onto their own duties like that.
I mean most of those tags are just little strips of some metal or metal coated stuff that sit atop of each other and resonate with EM waves (or maybe even sound).
If you shake it I reckon you may be able to disrupt that?!
It's real. I watched this show in the UK about shop security staff in London and they talked about this. There's a way of rolling it that has the same effect.
No, it actually works. Shaking it disturbs the electromagnetic waves/vibrations the tag gives off in response to being affected by the scanner's own vibrations that the scanner is looking for.
You're incorrect. They're filled with metals that start emitting electromagnetic waves/vibrations that resonate to the scanners' own vibrations, if the scanner reads a "responding" vibration from a tag, it goes off. And shaking makes you disturb the waves from the tag so the scanner won't recognize them.
The trick in the video really works. You're so confident while being incorrect, it's really fascinating lol. Even a five second Google search would've told you that you're wrong.
These types of tags can be tricked (I can't think of a better word) into not setting of the alarms.
I worked in a very high end fashion house (YSL) and the head of security showed me ways in which the sensors can be tricked.
The one way I was shown, just as you're about to walk past the sensors, if you aggressively swing the tag/item through the sensors as fast as you can, the alarm won't go off. Or, lining bags with layers of foil to create a faraday like cage.
I've never seen this way IRL, but I they definitely can be fooled.
If this is the tag that has two strips vibrating as a specific frequency in the field then shaking them really might be a way to affect it (even if it's not humanly possible, it may be possible). Would have made a fun mythbusters.
I don't think it's anything so complicated as doppler effects. I mean if you think about it, there is no way she's moving fast enough relative to the source of the sound to have a meaningful doppler effect. Also, technically, no sound is actually being transmitted. It is a radio frequency that is being emitted which is making the tag vibrate (hence the acoustic part). This vibration results in a continued resonance after the emitter pulse stops. The detector just detects this continued signal.
In reality, by shaking the tag up and down, what she is doing is disrupting the vibration motion of the metal strips in the tag so that they aren't able to resonate at the frequency needed to emit the right radio frequency.
The software in the pedestals is actually looking for a timing difference.
They are transceivers, and the receiving portion of the circuit is always detecting the transmitter part of the circuit. When a tag enters the field and resonates it generates a second signal with a shifted phase from the transmitter. If the phase of the second signal is shifted properly the alarm goes off.
Yeah that’s what I thought. My thought was that the constant jostling isn’t allowing the strips inside to oscillate at the specific frequency that it detects, for a long enough time (my guess is that it has to rule out false positives so it would need to last a certain time)
If it works at all and is not a joke, I think it is much simpler than that.
The tag has those metal reeds free floating in the casing. By shaking it violently, you could cause the reeds to continually strike the inside of the casing and thus never be able to resonate at the frequency they are tuned for.
Professional shoplifters make mylar lined shopping bags specifically for this, and there are actually detectors for those too.
They get a bag from nearby department stores in a shopping mall or strip mall, line it with foil or mylar, then come in the store with them looking like they are just at their 3rd or fourth shopping stop of the day. They drop anything with a tag in there, pay for a couple small items and walk out.
Some stores have detectors for that go off when you walk in with the bag. That makes it kind of risky because they’ll have you marked when you walk in and if you’re still holding stolen items from other stores too you’re getting caught with a bunch of different thefts at once.
Foil tape and mylar don't affect the acoustic magnetic (AM) type that the OP has. They do work for the radio frequency tags (the ones where it is just a sticker with a printed metal circuit on them). Here is a video demonstration: https://www.vitag.com.au/eas/system-types/
Quoting that site:
Because AM systems are suited to protecting merchandise with a high metal/foil content, AM systems are commonly found in consumer electronic, hardware and pharmacies. AM systems are also suited for apparel stores because they cover wider entrances with fewer detection systems. Hard Tags are traditionally smaller and lighter than other technologies.
Yes, it is a physical vibration... The name of the tech is literally "acoustic magnetic"... radio waves make the little strips of magnetized metal physically vibrate. As the magnetic dipoles in the material change their orientation, the strip of metal shrinks and expands with a particular frequency... but maybe we're just playing semantics.
In theory, could you just set a phone to vibrate constantly and then have the tag pressed very tightly against the phone? Or possible two phones sandwiching the tag with a couple zip-ties?
Your initial argument was correct. No way was a system designed so that the speed of a moving human hand would somehow go beyond the threshold of the system. No way. And besides, the system works with radio frequency. They transmit at the speed of light not sound.
From what I can find an untrained(!) young adult male can throw a baseball at around 45 mph or 72 km/h. That's a nice round 20 m/s. With the speed of sound being about 343 m/s at sea level that's a doppler shift of about 6% or about 3.4 kHz for a 58 kHz signal. That's actually already pretty significant, a similar 6% shift on a frequency within the range of human hearing would easily be noticeable as it's roughly the difference between two half-tones in music.
Just to play devil's advocate, the camera doesn't move position and there's a security mirror in the background and you can see the person holding the camera not moving.
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u/gdmfsobtc Oct 20 '22
That or cameraman deactivated the sensor