I have always said that the Korean police can remove these protesters any time they wanted, the ROK government just chooses not to until recently:
The defense ministry on Thursday brought non-weapon materials and construction equipment onto a Terminal High Altitude Area Defense (THAAD) base in central South Korea after riot police dispersed protesters opposed to the deployment of the American anti-missile defense system.
The shipments transported into the base for the THAAD system in the central town of Seongju, about 300 kilometers southeast of Seoul, included daily necessities for base troops and construction equipment and materials to be used to improve their living facilities, according to the ministry.
Their transportation was completed after riot police dispersed about 70 Seongju residents and civic activists, who had occupied a small bridge leading to the THAAD base from early morning to block any vehicles from approaching the military facility.
The protesters tied themselves up into ladder-like structures installed on the bridge to resist the police and shouted various slogans against THAAD.
The Democratic Party of Korea appears to really be enjoying the crackdown on their conservative critics:
Lee Nak-yon, the head of the ruling Democratic Party, said in a Facebook post Saturday that the police should work to prevent rallies planned for Hangeul Day, which falls Oct. 9. He thanked law enforcement for almost perfectly preventing illegal protests on Oct. 3.
“We are somewhat relieved at the moment, but some organizations have announced plans for more rallies on Hangeul Day,” Lee wrote, adding that preventing mass gatherings will help the country stay clear of the virus and shore up its struggling economy.
“Whatever the reason may be, illegal gatherings and deterring virus control measures are by no means acceptable. I hope the police do the same and block illegal rallies on Hangeul Day while preventing potential danger.”
It appears we may be beginning to see the playing of the anti-U.S. card by the Korean left:
Amid deteriorating inter-Korean relations, a South Korea-U.S. working group is taking flak for hampering progress in bilateral ties due to its excessively harsh standards adopted on North Korea.
Critics say unlike its initial goal of coordinating policy on the North, the group is obsessed with whether Seoul-driven initiatives to engage with Pyongyang violate economic sanctions on the reclusive state, with some even calling for its breakup.
The working group, co-chaired by Lee Do-hoon, special representative for Korean Peninsula Peace and Security Affairs and U.S. Special Envoy for North Korea Stephen Biegun, was set up in November 2018 following three inter-Korean summits earlier that year.
Upon its establishment, the government had high hopes that it would be in close communication with the U.S. via the organization. But due to Washington’s stern stance that inter-Korean economic cooperation should proceed in step with significant progress in denuclearizing the North, the group has been more focused on whether inter-Korean exchanges and cooperation violate international and U.S. sanctions.
You can read more at the link, but the Moon administration has been holding off on playing the anti-U.S. card because of the efforts of the Trump administration to work out a deal with North Korea. However, no deal to end sanctions was ever reached. The Kim regime has lost patience thinks now is the time to pressure the Moon administration to unilaterally violate sanctions. This is because the Moon administration firmly won the April parliamentary elections and the Trump administration is bogged down with a number of issues.
To unilaterally violate sanctions the Moon administration will need to set conditions to blame the U.S. for the new tensions with North Korea. Sending out the activist groups to blame the South Korea-U.S. Work Group is just the start of this effort.