Jack Teixeira was arrested by the FBI for leaking hundreds of pages of sensitive documents from the Department of Defense in an online chatroom. Teixeira had top secret security clearance and allegedly changed his method of uploading documents to avoid detection. The leak has damaged U.S. international relations and exposed weaknesses in the Ukrainian military. The Pentagon called the leak a deliberate, criminal act. The 21-year-old Massachusetts Air National Guardsman who leaked sensitive U.S. documents allegedly changed his plan to avoid detection, according to court documents related to the suspect's case. Jack Teixeira was arrested by the Federal Bureau of…