US authorities have arrested a 21-year-old information technology specialist named Jack Teixeira in connection with the disclosure of highly classified military documents about the Ukraine war and other top national security issues. The leak is believed to have started on the social media site Discord, where Mr Teixeira posted for years. Here's a look at the security breach that the Pentagon has called a "very serious risk to national security". Who is Jack Teixeira? Jack Teixeira is an airman first class in the Massachusetts Air National Guard. He was wearing a T-shirt and shorts when he was taken into custody...