An unprecedented leak of secret US Government reports has revealed how two trillion dollars of suspected dirty money snakes around the globe. This week on Background Briefing, Mario Christodoulou shows how terrorists and mobsters smuggle staggering sums of money through some of the world's largest banks - and often get away with it. This never-before-told story is the culmination of a 16-month-long investigation by 400 journalists for the International Consortium of Investigative Journalists.