Minister of Science and ICT Lee Jong-ho apologizes for the recent fire-induced server failure that caused inconveniences to Kakao users during a National Assembly audit of the ministry at the Institute for Basic Science in Daejeon, Tuesday. Yonhap

By Lee Kyung-min

Kakao is facing a severe backlash from consumers and regulators following a fire-induced service disruption of Kakao Talk, as a number of users are preparing for a class action lawsuit against the IT giant amid growing calls for a probe into its monopolistic status.

The service failure of the country's most-popular messenger app, and disruptions to the entire 134 services available on the online platform, are prompting a growing number of Kakao users to seek other service providers.

Data from Wiseapp, Retail and Goods, a real-time data analysis services provider, showed the user number of LINE, operated by local IT giant Naver, spiked to 1.28 million, Sunday, nearly tripling from 430,000 on Saturday.

The user number of Telegram, a cloud-based instant messaging app, surged to 1.28 million, Sunday, up from 1.06 million, Friday.

"People have no reason to use Kakao when they can find similar apps on the market right away," an industry watcher said. "They don't care how widely used Kakao services are. When it can't meet their needs and others can, they will not waste any more time."

The fire at an SK C&C data center in Seongnam, Gyeonggi Province, Saturday, led to the shutdown of electricity to Kakao's servers and the server outage lasted for over 10 hours. As of Tuesday afternoon, some of its services were still not available.

Further clouing Kakao's business prospects is the government's move to tighten scrutiny over the IT firm's market monopoly, the chief cause of key services grinding to a halt, including financial, mobility, commerce, music streaming, webtoon, social networking, email and blogging.

The Fair Trade Commission (FTC) said Tuesday that it is fine-tuning the specifics of a regulation whereby online platform operators will be penalized for abusing their market dominance.