A threat purportedly from international hacker network Anonymous to attack government websites on April 14 in fact came from a group of schoolkids without hacking skills.
The National Police Agency's Cyber Terror Response Center on Wednesday said it booked three people for obstruction of official business for threatening the attacks.
They were identified by their surnames Kang (17), Bae (14), and Woo (23), a university student.
According to police, Kang and Bae met on the official Facebook and Twitter pages of Anonymous in January this year. They planned to hack websites of government agencies, and recruited accomplices on social media from March 12 to 22.
They posted a video clip of their threat on file-sharing websites and YouTube.
A police spokesman said Kang told police he is a member of Anonymous, but since the group is loosely associated network, it is nearly impossible to determine whether that is true.
The police added none of the three appear to have any hacking skills.
Police became suspicious when Anonymous denied the attack plans.
Meanwhile, police are cooperating with the Philippines in investigating a 15-year-old Filipino for attempting to hack the National Computing and Information Agency on March 18.