SEOUL, South Korea (AP) — A massive theft of customer data from three major credit card firms in South Korea has shown security lapses in the financial industry.

First revealed by prosecutors, the theft of information linked to 80 million credit cards such as salaries, monthly card usage, credit rating and card numbers has sparked widespread public concern. Cardholders are flocking to bank branches and overloading call centers and service websites to find out if their information was stolen.