A former member of the US Air National Guard (USANG), Jack Teixeira, was sentenced to 15 years in prison for leaking hundreds of pages of classified national defence information online, the US Department of Justice said on Tuesday. Teixeira, 22, pleaded guilty in March to six counts of willful retention and transmission of classified information relating to the national defence, reaching a plea agreement with prosecutors that recommended a sentence between 11 and 16 years. A judge in Boston, in the eastern US state of Massachusetts, has now decided on a 15-year prison term. “Jack Teixeira repe…