You won't be shocked to hear about the primary suspect: North Korea. Defector Kang Chol-hwan (above) noted to the Wall Street Journal that the North might want to confirm whether people claimed missing or dead "are really in fact missing or dead." The authoritarian regime frequently punishes the families of defectors in a bid to discourage further departures, and a hack like this could help it find out if people were lying to cover up defections. North Korea has a history of targeting defectors.

This isn't a complete breach. Roughly 32,000 North Koreans have fled to the South since the truce that ended the Korean War, and it's not clear how many of the victims were relatively recent entries. Still, it's a disconcerting attack that could have long-lasting repercussions for defectors and their families.