Kathryn Haun put away the DEA and Secret Service agents who tried to make off with more than $800,000 in stolen bitcoin while investigating the darknet Silk Road marketplace. She talks about how the blockchain technology underlying Bitcoin made it possible to uncover their theft, why she believes blockchain will create a lot of good, and what she does when the very people behind tumblers and mixers -- technology that makes her work more difficult -- turn to her when they are the victims of crimes. Along the way, we learn about the habits of cryptocurrency criminals and get a fascinating view into the world of "breeder documents."