On September 23, 1990, South Korean army soldier Yun Seok-yang escaped the Defense Security Command with three floppy disks after roughly 80 days inside the organization. He took the materials to the National Council of Churches in Korea and disclosed them to a journalist before holding a press conference on October 4. Yun said the command was conducting illegal inspections of approximately 1,300 civilians, including politicians, journalists, professors, and students.
The disclosed records reportedly contained highly intrusive intelligence, including home layouts, entry and escape routes, and the residences of relatives. Yun also said the government had prepared files for immediate arrests if emergency martial law were declared, linking the surveillance operation to contingency planning against political opposition and civil society. He was arrested for desertion, later rearrested on the same suspicion in 1992, and remained imprisoned until October 1994. The source identifies him as a public-interest whistleblower, but does not provide details of a later judicial ruling, institutional reform, or disciplinary action against the officials involved.
