The Citizen Media Law Project (CMLP) is jointly affiliated with Harvard Law School’s Berkman Center for Internet & Society, a research center founded to explore cyberspace, share in its study, and help pioneer its development, and the Center for Citizen Media, an initiative to enhance and expand grassroots media.

CMLP’s interactive database of legal threats contains lawsuits, cease & desist letters, subpoenas, and other legal threats directed at those who engage in online speech. You can view, search, create, and comment on entries in the database from their database page.

Perhaps one of the most useful resources is the Legal Guide for citizen journalists. You can lookup laws unique to each state.