A. 1) The Defendant’s national card, lot card, and Nong Bank are companies running businesses, such as credit cards, pre-paid cards, debit cards, issuance, sales, and management, and Defendant L (hereinafter “L”).

(1) The Credit Information Use and Protection Act (hereinafter referred to as the “Credit Information Act”) shall apply to a company incorporated jointly by a financial institution.

(2) The Plaintiffs are those who used or used a credit card, etc. upon entering into a contract for the use or financial transaction with Defendant’s national card, lot card, or one or three of the Nonghyup Bank, and a credit card company.

B. The concept of the card accident analysis system and the introduction card accident analysis system (hereinafter “FDS”) are introduced by all domestic credit card companies as a system to detect abnormal transactions or fraudulent use due to the theft, loss, forgery, etc. of credit cards.

According to the FDS, a large amount of card use information and customer information based on the past accident transactions created an analysis model in accordance with statistical techniques, based on this, and based on this, the card company will take measures such as refusing to grant credit card approval if the credit card is discovered due to any abnormal type of transaction according to an accident pattern analyzed in the course of using the credit card.

C. Defendant National Card’s customer information leakage 1) concluded a FDS development service contract and whether to provide card customer information) Defendant’s national card was necessary after the introduction of FDS for the first time in 2008, and entered into a purchase contract with L and FDS business on January 30, 2013.

B. L including M were engaged in the development of FDS from February 2, 2013 to August 2013, and among them, from February 2013 to March 2013, the Defendant’s national card located in Jongno-gu Seoul internal waters.