The World Tribune of 28 June 2020 reports on the fight sparked by North Korean defectors sending balloons with leaflets to their former homeland, which has brought both Koreas once again to the brink of war. Now Signe Poulsen, head of the Seoul office of the UN Office of High Commissioner for Human Rights, has stated that sending the leaflets is an exercise of the right to freedom of expression.

Both the North and South Korean governments have threatened the defectors in the South who have sought to counter communist “fake news” by sending real news North over the DMZ. The leaflets also often contain U.S. one-dollar bills and USB memory sticks meant to encourage North Koreans to pick up the leaflets.
Now the defectors have been targeted by hastily-passed legislation forbidding the practice. Poulsen made the remarks amid heightening tensions on the Korean Peninsula after the North threatened to retaliate against the South for what it called Seoul’s “connivance” at the floating of anti-Pyongyang materials in large balloons.
The government of South Korean President Moon Jae-In, sought to legislate a ban on leafleting and filed a criminal complaints against two defector groups who carry out such launches, the Korea Times reported on June 23. The provincial government of Gyeonggi, located near the border with the North and where a lot of leafleting takes places, issued an administrative order last week banning the entry into border areas to fly leaflets.
See also: https://humanrightsdefenders.blog/2015/04/21/the-interview-sequel-plays-at-the-korean-border/
and
https://en.wikipedia.org/wiki/Balloon_propaganda_campaigns_in_Korea