[Only recently, thanks to the restoration of net neutrality, have ISPs been able to legally avoid the nightmarish scenario of restricting their competitors' traffic. Companies like KT, the South Korean ISP recently accused of planting malware on 600,000 of its own customers.

According to a report by South Korean news agency JTBC, users of torrent-based "webhard" services (a popular file storage and transfer platform in South Korea) began reporting slow transfer speeds, corrupted files, and broken PCs in 2020. One webhard provider realized that all of the users experiencing problems were KT customers and reported the information to South Korean law enforcement.

ISPs have been battling torrent traffic for years. In the U.S., years before the FCC decided to move things along without net neutrality (it didn't work), Comcast throttled BitTorrent transfers in 2008, then earned itself a stay and an appeal. Advances in legal protections and networking have somewhat dampened these efforts in recent years, making it even more ridiculous that Korean police found evidence suggesting that KT was distributing malware to its own customers as punishment for using P2P services.

According to a follow-up report by JTBC, a search of KT's headquarters revealed that the ISP had formed a team to develop and distribute malware, allegedly "eavesdropping" on data exchanged between KT subscribers accessing webhard services and interfering with their transmissions... Since there is no English-language coverage by JTBC

While it is difficult to confirm the details, the explanation regarding KT's anti-malware team appears to be that it was an attempt to control what the team considered a "malicious service" and that only a few people were involved.

According to the police investigation, the anti-malware team's activities followed KT's internal discussions about minimizing ongoing network costs, and dozens of devices were allegedly involved, raising questions about how isolated the activities were within the company. I am no expert, but if it were me, would I have tried some IP ban instead?