South Korean prosecutors have indicted an engineer accused of stealing the credit card details of more than 20 million people and selling them to marketing firms.
The engineer allegedly used his position at the Korea Credit Bureau to access databases belonging to KB Kookmin Card, Lotte Card, and NH Nonghyup Card between May 2012 and December 2013.
The crook copied the card numbers and expiry dates of NongHyup and Lotte customers, but not Kookmin, onto a USB stick. E-mail and residential addresses and phone numbers were also taken.
The information was then sold to marketing firms. Officials at these firms have also now been arrested.
South Korea's Financial Supervisory Service says that the chances of fraud are low because PINs and CVCs were not taken in the theft but any losses will be covered by the card firms.
The bosses of all three companies have made public apologies and several executives have tendered their resignations. According to Bloomberg, 27 people from KB Kookmin Card and its parent have offered to quit.