Siva Vaidhyanathan has written a great article in The Chronicle of Higher Education about the evolution of copyright law. A brief excerpt from his piece:
"Back in the 20th century, if someone had accused you of copyright infringement, you enjoyed that quaint and now seemingly archaic guarantee of due process. Today, due process is a lot harder to pursue, and the burden of proof increasingly is on those accused of copyright infringement. For the copyright act, in essence, makes the owner of every Internet service provider, content host, and search engine an untrained copyright cop. The default action is censorship."