Choose The Stickman
Each day a new part of the story is posted at @choose.the.stickman and @Choosethestickman. Viewers vote on what happens next by commenting on the latest part. The most popular choice writes the next part, and one commenter from the winning side can appear in the story with their username and public profile picture.
This site holds the legal pages for the small tool that reads those public comments and publishes the daily video.