Jack Teixeira: National guardsman suspected to be behind US military document leaks arrested

How could a 21-year-old reportedly have access to classified documents?
Jack Poso has the answer to the question we are all asking.
The 21-year-old, who is reportedly a member of the intelligence wing of the Massachusetts Air National Guard, is said to be the leader of an online group in which the leaked documents were shared.
Jack Teixeira, 21, is said to have overseen a private online group, containing around 25 active members, in which the highly classified documents were shared.