One of the best articles I've come across on unsolicited commercial email (aka spam) is from the pages of the United Kingdom based Journal of Information Law, and Technology. Spam Law for the Internet is written by W K Khong (a lecturer at the Multimedia University in Malaysia), and is in-depth, informative, and up-to-date. The abstract from the article reads as follows:

"This paper briefly surveys the movement to regulate spam or unsolicited commercial emails on the Internet. It discusses the history of spam, definition of spam, and identifies parties fighting spam. Also, it examines legislative efforts in the European Union and the United States to regulate spam and the various schemes and mechanisms employed."

- William Slawski