Security Advantage

How are magnetized security features on items in stores disabled by just scanning the barcodes?

From what I understand there are these thin metal strips on goods in stores for security in catching shop-lifters.' If this is how items with such security features are detected by the high frequency detector gates located by the doors of stores, then how are these magnetized items disabled simply by scanning their barcodes when purchased?

Public Comments

1. Hidden under the scanner is a very powerful magnetic pad. It's the thing that has the warning about keeping credit cards away from it.
2. Each thin metal strip contain a data (mostly a sort of serial number, stored as induced magnetic pattern). And when it is scanned, the data from the metal strip will be retrieved, then the cashier computer will connect to its network, and modify its items database, allowing the corresponding item to be registered/marked as paid/purchased. When someone walk through a detector gate, the high frequency wave produced by the gate will be reflected by the magnet according to the data it contains (the reflected wave will have sort of pattern). The serial number of the item will then be identified by the detector gate. Then, a computer in the detector gate will access the store's database to see whether the item with that serial number has been purchased or not. If it has been purchased, it will stay quiet. Otherwise, it will ring. Hope this helps :)
3. Look up RFID.