My thesis actually deals with this topic a lot in relation to copyright and theatre. The Actors Equity Association is freaking out and trying to pull all of the clips of Broadway shows that audience members have recorded illegally from youtube. They claim it could hurt ticket sales, but actually since youtube was launched, ticket sales have increased! I argue in my thesis that the bootleg recordings are actually helping the industry rather than hurting it because it introduces the show to people who may never have heard of it and fosters fandom creation! :)