A. 1) The Defendant is a stock company engaged in the business of issuing, selling, and managing credit cards, pre-paid cards, debit cards, or debit cards. 2) H stock company (hereinafter “H”) is a company incorporated by financial institutions through joint investment, and is engaged in business of credit inquiry and credit investigation as prescribed by the Use and Protection of Credit Information Act.

3) The Plaintiffs are those who have used or used a credit card, etc. upon entering into a contract for use and financial transaction with the Defendant. B. The concept of the card accident analysis system and the introduction 1) card accident analysis system (hereinafter “FDS”) are introduced by all domestic credit card companies as a system to detect transactions or illegal use as long as it is caused by theft, loss, or forgery or alteration of credit cards.

2) According to the FDS, an analysis model is made based on statistical techniques using a large amount of card use information and relevant customer information based on the past accident transaction, and based on this, if it is discovered that abnormal types of transaction have occurred according to the type of accident analyzed on the basis of statistical data at the time of using the credit card, it is possible to refuse approval of the card. (c) After the introduction of FDS in 208, the Defendant entered into a contract with H on January 30, 2013 with the FDS 27,419,50 won, and the delivery deadline was determined within seven months from the date of conclusion of the contract.

2. The development human resources of H, including I, who are the general manager of the project, were put into the Defendant from February 2, 2013 to August 2013, and started the FDS development work. ① From February 2013 to April 2013, it is necessary to consult and define the Defendant’s claims management division and work requirements, and thus, at the Defendant K head office located in Jongno-gu Seoul High Court.