South Korea’s state media regulator on Wednesday ordered Facebook to pay a 396 million won ($369,600) penalty for deliberately rerouting SK Telecom, SK Broadband and LG Uplus’ network connection to the social networking site, and causing a slowdown for local users.

The Korea Communications Commission said that it considered Facebook’s actions as a breach of Korea’s telecommunications law, and ordered the firm to correct its practice and pay an administrative penalty.

The KCC launched an investigation into Facebook in August 2017, after internet service provider SK Broadband accused Facebook of cutting off access to a cache server operated by KT, causing a slowdown for SKB subscribers using Facebook.

The issue first emerged in 2016, when Korea’s Ministry of Science and ICT changed the country’s network-sharing regulations, causing payment issues among local internet service providers and firms like Facebook.

Facebook had been paying KT for using the cache server, which saves online content locally in a temporary storage, to grant Korean users a faster connection speed to the social network. Access slows down when directly connecting to Facebook’s server in Hong Kong.

SK Broadband and LG Uplus had been using KT’s cache server to connect to Facebook, but their access was cut off, and redirected to the slower Hong Kong server, without sufficient discussion or an agreement.

According to the KCC, Facebook rerouted SKT’s network to the Hong Kong server in December 2016, and rerouted LG Uplus’ network to servers in Hong Kong and the US from January to February of 2017.

With SKT’s user traffic rerouted to Hong Kong, it strained SKB’s network, causing the connection speed to Facebook to become 4.5 times slower for SKB subscribers, compared to before the rerouting. For LG Uplus subscribers, the connection speed became 2.4 times slower.

As a result, Koreans subscribed to the two networks experienced inconvenience in accessing Facebook’s services, the KCC said.

According to the Korean media regulator, Facebook did not actively make due efforts to resolve the issue and improve its connection speed. As a result, the Korean internet service providers had to pay extra to handle the extra overseas network traffic.

It was not until October and November 2017 that Facebook returned the network connections to their original arrangements, according to the KCC.

As a result, the media regulator viewed Facebook’s actions as a breach of the local telecommunications law -- limiting or terminating a telecommunications service without due reason.

By Sohn Ji-young (jys@heraldcorp.com)