''The Supreme Court on Wednesday upheld a federal law that restored copyright protection to works that had entered the public domain.

By a 6-to-2 vote, the justices rejected arguments based on the First Amendment and the Constitution’s copyright clause, saying that the public domain was not “a category of constitutional significance” and that copyright protections might be expanded even if they did not create incentives for new works to be created.''

http://www.nytimes.com/2012/01/19/business/public-domain-works-can-be-copyrighted-anew-justices-rule.html?_r=2