Yonhap news agency reported on Friday that the head of the largest labor union at Samsung Electronics, along with a senior union official, is under investigation for allegedly pilfering personal data belonging to roughly 100,000 employees to compile a so-called "union blacklist." According to the report, the Hwaseong Dongtan Police Station in Gyeonggi Province has referred the union's president, Choi Seung-ho, and another unnamed senior union figure to prosecutors on charges of contravening the Personal Information Protection Act.

Choi and the other official are accused of leveraging illegally obtained employee records—which included details about workers' union membership status—to draft the blacklist. The list is believed to have been assembled around March, at a time when the union was gearing up for a general strike over performance bonuses. The unnamed union official, who had access to the company's internal systems, is suspected of unlawfully acquiring a file containing the names of more than 100,000 employees and handing it over to the union.

On April 10, Samsung Electronics filed a police complaint against several union-related officials, alleging they extracted and disseminated employee information unrelated to their job duties. The company then lodged an additional complaint on April 16 against the involved union official, accusing them of systematically collecting vast amounts of personal data via the internal system and supplying it to outside parties. Samsung stated that this official accessed the internal system approximately 20,000 times within a single hour to view staff details.

Following nearly five months of investigation into evidence indicating Choi's involvement in creating the union blacklist, police decided to press charges against the two individuals. On the same day, authorities also referred four other Samsung Electronics employees to prosecutors for improperly accessing the company's internal systems in violation of personal information laws. These four individuals reportedly queried the union membership status of other workers out of mere curiosity, but did not organize or distribute the information they found.