Interesting TED talk if you are interested in the underground economy or the economics of crime.
Loretta Napoleoni details her rare opportunity to talk to the secretive Italian Red Brigades -- an experience that sparked a lifelong interest in terrorism. She gives a behind-the-scenes look at its complex economics, revealing a surprising connection between money laundering and the US Patriot Act.
http://www.ted.com/talks/loretta_napoleoni_the_intricate_economics_of_terrorism.html