Insane Clown Posse, the Detroit rap duo made up of Violent J and Shaggy 2 Dope, can add "tech startup founders" to their fantastically long resumes: they've founded a social network called Juggalobook, which is, as you expected, Facebook for their fans (called juggalos and juggalettes).
It's still a little buggy and looks like it was designed in 2001, but it seems like a pretty rad place for juggalos and juggalettes to hang out. Whereas Facebook asks you, "What's on your mind?," Juggalobook asks, "What up ninja?" "Friends" are "homies" and "Likes" are "whoop whoops!," and there's no Facebook-style comment moderation. Additionally, every Juggalobook user shows up on every other Juggalobook user's timeline, so there's no point in adding someone else as your "homie" unless you really just want the rest of the world to know.
Anyway, here's the video for the group's 2010 viral video "Miracles," so you can remember why exactly you wanna join Juggalobook in the first place.
Insane Clown Posse - "Miracles"