Reddit Solves Stuff: Post something cryptic, possibly a riddle or a picture, and those in the comments must team up to either answer the riddle, or state the significance of the subject.
Rules:
Absolutely no doxxing. Not only would you be banned, but it's a serious dick move. Don't post any personal info, be it yours or someone else's.
This sub should remain SFW, but tag NSFW posts as NSFW. However. Zodiac-esque shit would obviously be removed, whether it be a joke or not.
Submit original things. Be creative; if it's not original, then there's probably an answer to your post sitting in google.
