What rights do authors have over internet content on websites like Youtube?

When a company holding copyright over infringed material recovers damages from another company they accuse of infringing on their copyrighted material why shouldn't the authors, actors etc. be entitled to a share of the recovered damages in the same way they are entitled to royalties from ordinary use? Striking Hollywood screen-writers raise an interesting (and entirely self-interested) point:

http://www.youtube.com/watch?v=PzRHlpEmr0w