Victims of the personal data leak at the matchmaking company Duo have filed the first class-action damages suit against the company, according to confirmations. The claim amount is 1 million won per victim. The assessment took into account that not just contact information but a large volume of data closely tied to private life—such as marital history, salary, education, and physical information—was leaked.
According to legal sources on the 7th, LKB Pyeongsan, representing 46 victims of the Duo personal data leak, filed a class-action damages suit with the Seoul Central District Court the previous day. It is the first class action filed over the Duo personal data leak.
The Personal Information Protection Commission said on the 23rd that a Duo employee's work PC was infected with malware, resulting in a leak of personal information belonging to 427,464 full members. The leaked data reportedly included not only basic information such as IDs, passwords, names, dates of birth, contact details, and addresses, but also marital history, height, weight, blood type, religion, hobbies, sibling relationships, education, and workplace information.
The Personal Information Protection Commission (PIPC) found that Duo neglected its duty to implement safety measures to protect personal data, such as access management for databases, and imposed a penalty surcharge of 1.197 billion won.
Following the PIPC's announcement of its investigation results, legal sources assessed that this case is different from ordinary personal data leaks. Given the nature of the member information held by a matchmaking firm, details could reveal an individual's private life, family relationships, financial status, and marital history. There were also concerns that, if the leaked personal data is misused, it could likely lead to secondary crimes.
This is also why LKB Pyeongsan set the damages claim at 1 million won per victim. LKB Pyeongsan said it comprehensively considered the scope and sensitivity of the leaked information, the victims' mental distress, and the possibility of secondary harm. Compared with the typical 100,000 to 500,000 won claimed in cases involving only contact information leaks, this is a higher amount.
According to a notice posted on Duo's website the previous day, those affected by the data leak are members who joined before Jan. 27, 2025. Duo said it is individually notifying victims whose contact information has been confirmed. The potential leak items disclosed by Duo reportedly include, in addition to basic personal details, optional information such as registered domicile address, head of family name, reason for remarriage, year of divorce, actual duration of marriage, reason for divorce, former spouse's name, number of children currently being raised by the person, whether the person owns a car, and personality traits.
LKB Pyeongsan said more people are joining the suit and it plans to file follow-up actions. Jung Tae-won, head of the LKB Pyeongsan Class Action Center, said, "Given the sensitivity of information held by matchmaking firms, their responsibility can by no means be taken lightly," adding, "Many victims raising their voices together will serve as an opportunity to underscore the importance of personal data protection."