Cicada 3301 is perhaps the most mysterious seemingly Internet-based organization in the history of online mysteries. Since 2012, the group has posted numerous puzzles online under that name and has made no reference as to what it does or even where it is from. No one knows who runs it, assuming it really is an organization, or even the name of a single member. Cicada 3301 is able to keep its reputation with so little information strictly because of the interesting scavenger hunt of sorts it has released for three years running.
It all started on January 5, 2012 when a 4chan user posted a steganography clue on the “random” board. The image stated that Cicada 3301 was looking for “intelligent” people. In fact, the word used was “recruiting.” For what, no one has said and Cicada 3301 is certainly keeping it a secret. The image hid a clue that takes some level of specialized knowledge to find. It involved a Caesar cipher, which is pretty standard crypto, but the rest took at least some technical knowledge.
From there, and in future puzzles, clues varied greatly in skill-set necessary for solving and even location. Some of the clues were in physical locations, making it necessary for people who could not reach the clues to use posts on the Internet to get further in the hunt. Moreover, some of the references in the clues are pop culture, literature and other non-tech topics.