It’s becoming an organized crime tactic:
Card draining is when criminals remove gift cards from a store display, open them in a separate location, and either record the card numbers and PINs or replace them with a new barcode. The crooks then repair the packaging, return to a store and place the cards back on a rack. When a customer unwittingly selects and loads money onto a tampered card, the criminal is able to access the card online and steal the balance.
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In card draining, the runners assist with removing, tampering and restocking of gift cards, according to court documents and investigators…
This article has been indexed from Schneier on Security