In Trevor Paglen's new book, Blank Spots on the Map: The Dark Geography of the Pentagon's Secret World, he investigates the "off the map" locations of covert government activity: including the "salt pit" in Kabul where Khaled El-Masri was held.

Ben Wizner is El-Masri's lawyer, from the ACLU's National Security Project, and he joins Paglen in studio with Laura to talk about black sites, government secrecy, and why anything goes when prisoners are taken off the map.