Seoul: Kakao Corp., the operator of South Korea's dominant mobile messenger, has filed an administrative lawsuit against a government fine of 15.1 billion won (US$11 million) over the leaking of personal information on a large scale, according to sources Monday. The Personal Information Protection Commission, the government's personal information watchdog, imposed the fine in May, attributing the data breach of approximately 65,000 users to Kakao's inadequate data scrutiny and protection measures. According to Yonhap News Agency, Kakao has contested the fine by filing an administrative suit on November 1. This penalty is more than double the previous record fine of 7.5 billion won, which was levied on Golfzon, a screen golf business, by the same watchdog. Kakao had previously announced its intention to explore various response strategies, including the possibility of an administrative suit, in reaction to the commission's order.