From the team that brought you Paper Ghosts, Crossing the Line with M. William Phelps is a weekly true crime podcast that dives deep into cases that have rarely been covered. Learn more about your ad-choices at https://www.iheartpodcastnetwork.com

How do people become spies -- and why do some people end spying against their will? In the second part of this two-part series, Ben and Matt dive into the present state of spying, along with the troubling trends looming on the horizon. Learn more about your ad-choices at https://www.iheartpodcastnetwork.com

A caller asks for more information about the infamous Phoebus cartel. Road Dog asks about what people are supposed to do with all that urine collected from potty-trained cows. Mario, Schneider and Kevin write in with their own strange, disturbing stories. All this and more in this week's Listener Mail. Learn more about your ad-choices at https://www.iheartpodcastnetwork.com

Most people know the life of a real-life spy bears little resemblance to the stories of fictional agents like James Bond -- but what exactly is spying? In the first part of this two-part series, the guys explore the world of tradecraft from the ancient past to the modern day. Learn more about your ad-choices at https://www.iheartpodcastnetwork.com

What's the future of online privacy? Filmmaker Alex Winter joins Matt and Ben to talk about his new documentary "Deep Web", following the story of the infamous Silk Road and its creator, Ross Ulbricht. Learn more about your ad-choices at https://www.iheartpodcastnetwork.com