I work at a best buy, and earlier today security caught a guy with a foil-lined bag trying to shoplift some airport extremes in my department. i would love to see the guy trying to walk out and setting off all the alarms literally standing next to our loss prevention guy. i've never heard of these before, but isn't aluminum non-magnetic? i don't see how it would affect the magnetic tags
The idea is to form a Faraday cage around the magnetic tag. That way when you pass the sensor it doesn't set it off.
but wouldn't a non-magnetic material be as effective as cloth at creating a faraday cage for a magnetic sensor?
hmm i would have thought it would have to be a cage with that same properties as what you're blocking, magnetic cage for magnetism, conductive for electricity, etc. maybe i'll turn to a life of crime
Mmm works wonders, we have loads of stuff nicked in this fashion at the place i work part time at. Very hard to get round too. Though we were playing with RF readers at uni last term and managed to defeat those with some tinfoil... a life of crime is clearly the next step... And however effective a copper bag would be, from the thieves point of view - it's far more expensive than bunging some tin foil from tescos into a carrier... RwD
What pitch of mesh would you use though? High-frequency systems would easily get through too big a pitch of mesh. Alu foil is cheap, easy to find and there's no particular wavelength that'll penetrate it without realistic attenuation.
not the first time ive heard of these bags, talk about a clever chap to have thought this one up. Finding a new application for an old technology. The difficult bit is getting said item into such bag, its this transition that is usually picked up on camera or visually by store detectives. best one i saw recently was a classic grab and run at christmas time from a currys in a shopping centre, undercover security guard in the attempt at stopping the chap missed and tripped, whilst the thief was laughing he got rugby tackled by 3 by standers, pure ownage! kinda looked like this, so funny i hurt myself laughing!
Haha the pictoral example helped, also I hate shoplifters, never met any clever enough to understand the faraday principle either
Well then... how about we just go to a bag made out of the thick layer of lead that is used in X-ray protection? Might be a little hard running out of the store but atleast it could double as a weapon against the security officer
This is why I love bit-tech.net - a discussion about shoplifting rapidly turns into a discussion about how practical a copper lined purse would be as a Faraday cage.
Best thing to do (I would imagine ) is just walk out, ignoring the alarm. Seriously, these scanners are the new car alarms. Most of the time they go off because the inventory tag has not be removed/neutralised. If it does go off it is generally a case of having to hunt around for someone to sort it out, rather than being rugby tackled by several security guards. Although fun can be had by planting an active tag somewhere on the person of someone you don't like
It depends, you've got to buy something if there's a security guard on the door, otherwise they'll know perfectly well you've nicked something.
