If you'd like to learn more about the issues involved in deep linking, you may want to visit these sites:

Universal: Don't Link to Us - Wired News - article about the Universal/Movie-Link controversy

More on "deep links," journalists and IPOs -  more on technical methods which could be used to prevent deep linking

Linking Rights - addresses the part that copyright laws play in the deep linking dilemma

Link Law: The Emerging Law of Internet Hyperlinks - very comprehensive site that explores every linking sin you could ever commit

Hyperlinks, Frames, and Meta-tags: An Intellectual Property Analysis - a legal perspective from The Journal of Law and Technology

The Link Controversy Page - covers problems in the area of copyright, trademark, trespass law as well as unfair competition law