In New York Times v. Tasini, the US Supreme Court extended copyright so that freelancers would have control over placement of their works in electronic database versions of print journals, for example, when the New York Times made its issues (including the work of freelancers) available through Nexis. Jeffrey Rosen explains (Freelanced) in The New Republic why the Supreme Court was wrong. Rosen is right, mostly, but it is hard to sympathize with the publishers. Enforcing this new right is not going to be easy, but the National Writers Union has filed a new lawsuit against the New York Times (Freelancers Plan Return to Court) in order to try.
The National Writers Union has a guide to the issues.
Wired coverage (Freelancers Fear Blacklisting).