"George Lucas built a whole new industry with Star Wars." says Peter S. Menell, devoted science fiction fan and a professor at the UC Berkeley School of Law, who studies copyright and intellectual property law. "But what funds that remarkable company is their ways of using copyright."
And he's right. A third of the profits LucasFilm pulls in from Star Wars has come from merchandising alone (http://www.forbes.com/sites/aswathdamodaran/2016/01/06/intergalactic-finance-how-much-is-the-star-wars-franchise-worth-to-disney/#74c6181b2d79). Not ticket sales, not DVDs, not video games or books. Toys, clothes, and weird tie-ins like tauntaun sleeping bags and wookie hair conditioner.
But fans of Star Wars, and other stratospherically profitable creative universes, increasingly like to become creators within those universes. They write books, they make costumes, they direct spinoffs and upload them to YouTube.
And sometimes they make money.
How does law come into play when fans start to reint