[Invest&Law] Jium and LKB Pyungsan Represent 420,000 Duo Members in Data Leak Lawsuit

Published 06 May.2026 08:14(KST)

Class Action Recruitment for Data Leak Victims

Retainer Fee of 10,000 Won, Success Fee Applicable Upon Winning

The large-scale personal data leak at Duo, a matchmaking company, has escalated into a class action lawsuit, with law firms successively stepping forward to represent plaintiffs in the collective legal action.

According to the Personal Information Protection Commission on May 6, a data breach occurred, exposing the personal information of all 427,464 full members of Duo. In January last year, a hacker planted malware on an employee's (personal information handler’s) work PC, obtained the database (DB) server account information, and subsequently accessed the member database. The exposed information reportedly included highly sensitive items such as names, resident registration numbers, mobile phone numbers, as well as height, weight, blood type, religion, marital history, sibling relationships, educational background and major, and workplace.

The Personal Information Protection Commission imposed a fine of 1,197 million won and a penalty of 13.2 million won. The commission ordered the implementation of breach notifications, the establishment of guidelines for personal information handling and destruction, and the strengthening of the overall personal information protection and management system. Law firms Jium and LKB Pyungsan are representing plaintiffs in the class action lawsuit related to this incident. The retainer fee is set at 10,000 won, and a success fee will be charged in the event of a win. Jium aims to win the full amount for each plaintiff, starting with a claim for 500,000 won in damages per person and expanding the final claim amount before the conclusion of the first trial to '1 million to 3 million won in damages plus economic losses,' depending on the evidence of specific damages (such as economic loss) and whether secondary damages occurred.

A representative from Jium stated, "Jium has handled major cases with the Fair Trade Commission, represented victims of stock price manipulation, and achieved victories in class actions such as those involving traffic bans at Uijeongbu West Road and Boryeong Undersea Tunnel." The representative added, "We are currently providing advisory services and legal representation to the Personal Information Protection Commission, so we can leverage this experience to handle the case with the highest level of expertise. Given that sensitive information such as marital history, family relationships, and workplace has been leaked, we are determined to pursue the maximum statutory compensation in court."

The law firm LKB Pyungsan is also recruiting participants for the class action. LKB Pyungsan stated on its website, "The mass leakage of sensitive information, delay in breach notification and lack of management and supervision, collection of prohibited information and violation of the obligation to destroy data, and the risk of secondary damages are important factors that can increase the amount of compensation."

LKB Pyungsan will first pursue damages under Article 39-2 of the Personal Information Protection Act (claim for statutory damages) for those whose financial losses have not been confirmed, and will file for punitive damages (up to five times the amount) under Article 39, Paragraph 3 of the Act if financial losses and requirements are substantiated in the future. The retainer fee is 10,000 won, and a success fee, determined by the court level, will apply if the case is won.