How Telegram Became the Underworld’s Favorite App

A Times investigation has found that Telegram, one of the world’s biggest messaging apps, with nearly a billion users, is also a giant black market and gathering place for the likes of terrorists and white supremacists. Adam Satariano, a technology reporter for The Times, discusses the story of Telegram and the arrest of its founder, Pavel Durov. Guest: Adam Satariano, a technology correspondent for The New York Times.