Beyond their songs or record sales, the greatest legacy of One Direction, a new book argues, might be their massive, passionate, predominantly female fanbase. Kaitlyn Tiffany, a staff writer for The Atlantic, joins us to discuss her new book, Everything I Need I Get From You: How Fangirls Created the Internet as We Know It, which examines how our lives online are shaped by the behavior of fan communities, and the good and ill that can come from these groups.