On 18th January 2023, the National Intelligence Service (NIS) and the national police of Korea raided the office of the Korean Confederation of Trade Unions (KCTU) for 10 hours, alleging that two KCTU members from Korean Metal Workers Union (KMWU) and Korean Health and Medical Workers’ Union (KHMWU) violated the National Security Act. The KCTU is one of the largest workers’ organizations in South Korea.

The KCTU central executive committee members held a press conference on 19th January 2023, in protest of the raid. KCTU's President said that the raid was "not only disproportionate but also intended to intimidate the trade union movement." On 20th January, dozens of NIS agents raided the KCTU head office building for hours.