In conversation with Brennan Center fellow Mike German, John Mueller and Mark Stewart examine and evaluate the costs of the massive counterterrorism enterprise put in place since 2001, focusing on the efforts by police and intelligence agencies to follow up on over 5,000 tips flooding in each day. Mueller and Steward dive into the important questions rasied in the book: is this massive counterterroism effort necessary or effective? Or does this "ghost" chasing harm our society in ways we don't always consider when examining the impact of the terrorist threat?