KT's unauthorized small-sum payment incident is spreading, but subscriber churn has not become pronounced.
According to the Korea Telecommunications Operators Association (KTOA) on the 12th, from the 4th, when the incident was reported, to the 11th, 18,387 customers moved their numbers from KT to other carriers. Considering the 18,167 customers who moved from SK Telecom and LG Uplus to KT during the same period, the net decrease is only 220.
SK Telecom and LG Uplus saw net increases of 182 and 38, respectively, but given that the three mobile carriers usually exchange subscribers in the tens to hundreds per day, this is not unusual.
When a large-scale hacking incident broke out at SK Telecom in April, the situation was different. Immediately after the incident was disclosed, the net decrease was 20,000 to 30,000 per day, and more than 330,000 left in a month. By contrast
One reason churn has been limited in the KT incident is that a series of security breaches has dulled vigilance. Anxiety was high after the SK Telecom incident, but frequent incidents have led to fatigue, so the sense of crisis was weaker this time. The relatively limited scale of damage also played a role. KT said 19,000 customers received illegal femtocell signals, but it estimated that actual subscriber identity information (IMSI) leaks affected 5,561 people. The damage was concentrated in Seoul's Geumcheon District and in Gwangmyeong and Bucheon, Gyeonggi Province, and did not spread into nationwide fear.
The perception that "other carriers are not safe either" also appears to have played a role. There is also talk that SK Telecom, KT, and LG Uplus have all experienced security incidents large and small, spreading resignation that the risks are similar even if customers switch providers.
In addition, practical constraints such as the hassle of number portability, long-term contracts, and bundled products are factors that restrain churn. However, since KT denied any personal data leak until the 10th and belatedly acknowledged part of it, if subsequent investigations expand the scope of damage or reveal additional circumstances, public opinion could worsen and a delayed wave of subscriber moves could occur.
In particular, if a penalty waiver is implemented as in the SK Telecom case, the scale of churn could grow. An industry official said, "It is difficult to conclude customer loyalty from short-term figures alone," and added, "Mid- to long-term shifts will be determined by the additional scale of damage and KT's compensation plan."