Copyright is not exactly a tech topic, but it is a topic important to bloggers and techies. Scientific Blogging offers a discussion of the history and interpretation of copyright law in the United States. It can be found here.
The competition between copyright protection and free expression existed long before digital files and the Internet, and Snow reached back more than 150 years to document the history and evolution of the tension between the two. His research revealed that the burden to show whether a copier’s use of expression was fair initially lay with the copyright holder. For more than a century of common law, courts provided a liberal doctrine of fair use by imposing the burden of proof on copyright holders.
Copiers of expression were broadly protected from liability because the copyright holders had to prove that the copiers had made unfair use of the original expression. In this manner, courts conceived of the relationship between copyright, speech and fair use in a way that defined fair use as a right to protect speech.
By the 1950s, however, fair-use protection ceased to be broad, and the burden of proof began to shift to the user. Courts were influenced by commentary that framed fair use as an excuse for infringement, seemingly arising from the implied consent of the copyright holder.
If you use quotations in your work, whether digital or not, it’s worth a read.