Cicada 3301: An Internet Mystery
Cicada 3301 is an organization who used puzzles to possibly recruit codebreakers/linguists from the public. The first internet puzzle started on January 4, 2012, and ran for approximately one month. A second round began one year later on January 4, 2013, and a third round following the confirmation of a fresh clue posted on Twitter on January 4, 2014.