Copyright law's "fair use" doctrine aims to protect artists' First Amendment-informed rights by establishing the legality of their non-licensed citation or incorporation of copyrighted material of another author's copyrighted work into their own. However, ambiguities surrounding the function and extent of fair use, and the sheer legal expenses of clarifying these uncertainties on a case-by-case basis, frequently deny authors their First Amendment-based fair use rights. In the context of independent documentary filmmaking, a rigidly structured and highly expensive rights clearance culture generates many ethical ambiguities and thereby functions as a significant form of censorship.