US The Biggest Internet Mystery, Sochi's Record-Breaking Olympics, WWII Women Pilots Published January 5, 2014 at 5:20 PM EST Facebook Twitter LinkedIn Email Listen • 0:00 Cicada 3301A poster found in Warsaw shows a QR Code for a website related to the Cicada 3301 mystery. Listen to the Story Listen • 0:00 Copyright 2014 NPR