2025 was a bad year for South Korean telcos and victims of scams but one positive consequence was that South Korea now has one of the most aggressive anti-scam strategies of any country in the world. Market leading mobile operator SK Telecom received a shellacking after a data breach that even their CEO described as “the worst hacking incident in the history of the telecommunications industry” so it was inevitable that they would try to restore their reputation with any good news they could offer. Decide for yourself whether it really is good news that they have just reported a massive increase in the number of scam calls and SMS messages blocked by their systems before they reached customers.
- 250 million blocked voice spam and scam calls, a 119% increase year-on-year
- 850 million blocked SMS messages, a 22% increase year-on-year
The numbers are impressive, if suspiciously round. SK Telecom was also keen to emphasize the advanced AI-based nature of their scanning technology. Son Young-gyu, Head of SKT’s Security Governance Division, issued a pretty typical quote which can be summarized as “we keep getting better and better at stopping scams and spam but criminals also get more sophisticated too”. The problem with assertions like this is that they include a built-in excuse if controls fail to do their job. It is worth contrasting SK Telecom’s figures with other telcos around the world to get some additional perspective.
One especially intriguing contrast is between SK Telecom and the figures reported by Australia’s leading telco, Telstra. Australia has approximately half the population of South Korea but both countries are economically and technologically advanced, with governments that have been unusually explicit about their anti-scam policies, and the two telcos each have the largest share of their domestic markets. Telstra is also an interesting source of comparison because they began reporting figures about blocked calls long before most other telcos. So it is worth noting that the ratio of blocked calls to phone users is now similar for both companies, though the increase in Telstra’s call blocking has been more gradual than last year’s 119% rise at SK Telecom. In contrast, Telstra blocks fewer than 100 million SMS messages per year, far below the 850 million blocked by SK Telecom. The different traffic profiles and/or filtering algorithms causes SK Telecom to block 3.4 SMS messages per every blocked call, while Telstra blocks 0.44 SMS messages per every blocked call.
It is typical that governments and the public have a positive reaction to news about large numbers of communications being automatically blocked by networks. However, this is a short-term perspective. The massive worldwide rise in the number of blocked communications is a sign of underlying problems that are not being addressed. Organized crime syndicates responsible for scam communications are rarely brought to justice. The increasing automation of spam and scam campaign generation is making the high-volume abuse of networks increasingly viable for dodgy little marketing businesses as well as smaller criminal outfits. Leading fraud expert Endre Syvertsen of Telenor Linx observed last year that the huge increase in blocking is “not sustainable” and that it represents a threat to the industry’s reputation while advising that his own business had witnessed a 30% increase in the number of calls blocked year-on-year.
You can read SK Telecom’s press announcement here.
