Intelligence authorities and police have applied Article Four of the National Security Act in the indictments of four South Korean activists who allegedly campaigned against the government's procurement of F-35 fighter jets under orders from North Korea. 

The National Intelligence Service and National Police Agency stipulated Articles Four, Seven and Eight of the National Security Act when requesting arrest warrants for the four activists. 

Article Four aims to punish a member of an anti-government organization or individual who has received an order and commits any act to accomplish that order. 

Punishment for violating this article is the strongest compared to other articles in the security law, and includes capital punishment and life imprisonment. 

Three of the four activists were arrested on Monday for violating the National Security Act.