" The stolen cards originate from credit card security breaches, resulting in a big list of card numbers. These are later sold online in packs filtered to worki

" The stolen cards originate from credit card security breaches, resulting in a big list of card numbers. These are later sold online in packs filtered to working card numbers only, which can be purchased for about $10 per valid card. To be able to compile and sell these packs, the carders need to know which ones are valid. To do this, they will use an online store or service to place an order for the sole purpose of seeing if the charge goes through or not.