A. The status of the parties, etc. 1) Defendant A Co., Ltd. (hereinafter “Defendant A”).

Defendant B Co., Ltd. (hereinafter “Defendant B”) is a corporation that engages in the business of issuing, selling, and managing credit cards, pre-paid cards, or debit cards.

) The Credit Information Protection Act (hereinafter “Credit Information Protection Act”) is a company incorporated jointly by financial institutions.

(2) The Plaintiffs are those who signed a contract with Defendant A for the use and financial transaction of credit cards, etc. and used or used credit cards, etc.

B. The concept of the card accident analysis system and the introduction card accident analysis system ("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, it is necessary to establish an analysis model in accordance with statistical techniques using large amount of card use information and customer information based on past accident transactions, and to take measures such as refusing to grant credit card approval when it is discovered that abnormal types of transactions have occurred according to statistical analysis pattern when credit cards are used.

C. Defendant A’s disclosure of customer information in the FDS development service contract and whether to provide card customer information) Defendant A entered into a contract with Defendant B on January 30, 2013, setting the contract amount of KRW 227,419,500 with Defendant B on January 30, 2013, within seven months from the date of the delivery deadline.

B. The development human resources of Defendant B, including Defendant C, who is the general manager of the project, are put into Defendant A from February 2013 to August 2013 and work for the development of FDS.