They thought their crimes were untraceable. Then their dark-web empire collapsed.

When Bitcoin was first created, it was believed to be an untraceable form of currency. This promise attracted tons of bad actors — and it turned out to be untrue. Apple News In Conversation host Shumita Basu spoke with journalist Andy Greenberg about his new book, Tracers in the Dark: The Global Hunt for the Crime Lords of Cryptocurrency. Greenberg lays out how U.S. authorities used cryptocurrency tracing to take down some of the most prolific criminals on the dark web.