The US law enforcement officials have arrested a 21-year-old Air Force National Guard member who leaked a trove of classified government documents on instant messaging app Discord which is popular among teenagers.
The suspect, Jack Teixeira, was arrested from his home in North Dighton, Massachusetts, late on Thursday.
"The Justice Department arrested Jack Douglas Teixeira in connection with an investigation into alleged unauthorised removal, retention, and transmission of classified national defense information," it said in a statement.
The Biden administration will have a difficult time explaining how the largest US intelligence leak in a decade could have been committed by a 21-year-old airman whose job description - "cyber transport systems journeyman" - required a high school diploma, a driver's licence, and up to 18 months of on-the-job training.
How did a low-level Defence Department employee gain access to such sensitive information?
According to Bloomberg, Teixeira's position at the Pentagon was relatively junior. An Air Force job description says workers like him "keep our communications systems up and running and play an integral role in our continuing success."
According to his service record, he joined the Air National Guard in 2019.
This begs the question: If a low-level Defence Department employee has access to such sensitive information, who doesn't?
While President Joe Biden attempted to downplay the gravity of the leak, experts and former officials said it was a massive expose that revealed not only current assessments of the Ukraine war, but also how the US collects intelligence around the world.
One official from an allied country described how phones immediately started ringing after a Washington Post report on Thursday night described the leaker as a military buff who began sharing the documents with online friends and acquaintances - some of whom were just teenagers - in an apparent bid to avoid isolation during the coronavirus pandemic.
According to the official, it was a fresh reminder of a question that has dogged the US following a string of intelligence failures: whether the world's most powerful nation can keep a secret.
Pentagon first discovered the sensitive documents posted to Discord, Twitter and Telegram last week
The Pentagon first discovered the sensitive documents posted to Discord, Twitter and Telegram last week, which revealed details about the Russia-Ukraine war along with information about America's efforts to spy on Russia and its allies.
According to a report from The Washington Post, the original leaker was known as "OG" within the private Discord server "Thug Shaker Central," where he also served as the administrator.
