Defendant National Card, Nonghyup Bank, and Culture Card is a corporation that operates businesses such as the issuance, sale, and management of credit cards, pre-paid cards, and pre-paid cards (hereinafter “Defendant National Card Companies”), and Defendant E is a corporation that is jointly invested and incorporated by financial institutions, and is engaged in business such as credit inquiry and credit investigation as prescribed by the Act on the Use and Protection of Credit Information.

The Plaintiffs’ List is the entire Plaintiff in this case. Of the entire Plaintiffs in this case, the remaining part of the Plaintiffs, other than Plaintiff B, dismissed among the Plaintiffs related to the Defendant’s National Card, was classified as the Plaintiff’s List No. 2, and the remainder, other than Plaintiff B and C, which were dismissed among the Plaintiffs related to the Defendant Nonghyup Bank, as the Plaintiff’s List No. 3, and the Plaintiff’s remaining part, other than Plaintiff B, which was dismissed among the Plaintiffs related to the Defendant Culture Bank, was leaked on April 2010 and December 2013, respectively, as the Plaintiff’s List No. 4-1 and the Plaintiff’s List No. 4-2, respectively.

A person who has used or used a credit card, etc. after entering into a financial transaction contract with the defendant credit card company.

The concept of the F system and the introduction of the F system (hereinafter referred to as the "G") are introduced by all domestic credit card companies to detect abnormal or fraudulent use due to the theft, loss, forgery, etc. of credit cards. According to G, it is possible to establish an analysis model based on statistical techniques using large-scale card use information and relevant card customer information based on past accident transactions and to find that abnormal types of transactions have occurred depending on the statistical analysis of credit cards when using credit cards based on the results.

Defendant’s National Card.