Another section of the documents, from the C.I.A., is more explicit about how the United States has learned about the South Korean deliberations, noting the information was from “a signals intelligence report,” a term spy agencies use for any kind of intercepted communications from phone calls to electronic messages.
The first tranche of documents appeared to have been posted in early March on Discord, a social media chat platform popular with video gamers, according to Aric Toler, an analyst at Bellingcat, the Dutch investigative site.
Discord surged in popularity during the pandemic, and became a hub for young people to socialize and for music lovers, anime fans and cryptocurrency enthusiasts to discuss their passions in communities known as servers. By late 2021, the platform had more than 150 million active users each month.
Discord servers are essentially chat rooms, where people can discuss their hobbies and message each other or join audio calls. Some servers are public and contain thousands of people, while others are invitation-only. This setup has enabled Discord to thrive, but it has also caused the company to face problems with harmful content over the years.
Some of the documents were then reposted in the following weeks on other social media platforms including 4chan, an anonymous, fringe message board, but gained much broader attention only when they surfaced in recent days on Twitter and Telegram, analysts said.
On Saturday, pictures of many of the documents were still available on Twitter. While the social media platform in the past could have taken steps to remove the material, under rules that prohibited the distribution of hacked material, Elon Musk, Twitter’s owner, appeared to indicate in a Twitter post on Thursday that he would not delete the material.
Julian E. Barnes, Helene Cooper and Eric Schmitt reported from Washington, Thomas Gibbons-Neff from London and Michael Schwirtz from Lviv, Ukraine. Kellen Browning contributed reporting.
