Sending balloons filled with anti-regime leaflets into North Korea is nothing new. Activists had done that for decades despite constant complaints and even threats from Pyongyang. So it was shocking for Park Sang-hak, the head of Fighters for a Free North Korea, a rights group known for the campaign, to be informed about the Unification Ministry's decision to revoke the group's registration in July 2020 ― only several weeks after Kim Yo-jong, sister of North Korean leader Kim Jong-un, complained about Seoul's inaction.