Facebook Korea said Thursday that it has filed an administrative suit against South Korea’s media regulator’s decision to fine the social networking giant for causing a network slowdown that inconvenienced local users.

The social networking giant said it filed the suit against the Korea Communications Commission with the Seoul Administrative Court on May 13. It has also asked for a court order to freeze the execution of the penalty until a ruling is reached.

The move comes after the KCC issued Facebook Korea with a 396 million won ($367,000) penalty for violating the local telecommunications law in March, on grounds that it deliberately slowed down SK Broadband and LG Uplus’ network connection speeds to Facebook’s services while negotiating network usage fees.

According to a Facebook Korea official, the company decided to file the suit as it could not accept the KCC’s argument that the social networking firm had deliberately sought to hurt its users, whose satisfaction with Facebook is closely tied to the firm’s profits.

“Our users are our No. 1 priority. We do not accept the notion that we did something to hinder the Facebook user experience. Our goal is to deliver optimal performance, security and reliability when accessing Facebook for users around the world,” the official said.

The KCC’s conclusion came after it began investigating Facebook over allegations that the social networking firm had cut off SK Broadband’s access to a cache server operated by KT, causing a slowdown for SK subscribers using Facebook.

The issue traces back to 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 companies with data-heavy services like Facebook.

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

SKB and LG Uplus had been using KT’s cache server to connect to Facebook, but their access was cut off without notice, and rerouted to the slower Hong Kong server, as a result of payment issues among ISPs after the new 2016 networking-sharing laws.

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

Facebook Korea contends that it never intended to negatively impact network performance when it switched the network connection routes, according to the company official.

“We strive to deliver optimal performance for all our users. Our network and infrastructure teams around the world work with multiple partners, including Korean internet service providers, to establish peering, caching and other network solutions to achieve this goal," the company said in a statement.

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