Copyright law is important to every stage of media production and reception. It helps determine filmmakers' artistic decisions, Hollywood's corporate structure, and the varieties of media consumption. The rise of digital media and the internet has only expanded copyright's reach. Everyone from producers and sceenwriters to amateur video makers, file sharers, and internet entrepreneurs has a stake in the history and future of piracy, copy protection, and the public domain.

Beginning with Thomas Edison's aggressive copyright disputes and concluding with recent lawsuits against YouTube,...