A 21-year-old was arrested in connection with the leak of classified military documents.
The Department of Justice said Jack Teixeira was taken into custody in the Boston area on Thursday.
"Teixeira is an employee of the United States Air Force National Guard," Attorney General Merrick Garland said in a statement.
The publication interviewed a member of a chat group where the leaks were shown.
“He’s a smart person. He knew what he was doing when he posted these documents, of course. These weren’t accidental leaks of any kind,” the person, who wanted to remain anonymous, told the Post.
The person added that he believed the leaker posted the documents out of anger because he reportedly was upset that his work wasn't getting enough attention.
Discord said on Wednesday that it was cooperating with the bureau but declined to define the extent of its cooperation.
Although the documents came to light in the past week, the Netherlands-based investigative journalism group Bellingcat, a Scripps News partner, has reported that it has found evidence that some of the files had been posted on Discord as far back as January. Scripps News has not independently verified that information.
The Pentagon said on Thursday that it is working around the clock to understand the scope, scale and impact of leaks.