Re-copyright?

I want to hear more about how they rationalized this one:

Wired – Congress may take books, musical compositions and other works out of the public domain, where they can be freely used and adapted, and grant them copyright status again, the Supreme Court ruled Wednesday.

In a 6-2 ruling, the court said that, just because material enters the public domain, it is not “territory that works may never exit.”

The top court was ruling on a petition by a group of orchestra conductors, educators, performers, publishers and film archivists who urged the justices to reverse an appellate court that ruled against the group, which has relied on artistic works in the public domain for their livelihoods.

They claimed that re-copyrighting public works would breach the speech rights of those who are now using those works without needing a license. There are millions of decades-old works at issue. Some of the well-known ones include H.G. Wells’ Things to Come; Fritz Lang’s Metropolis and the musical compositions of Igor Fyodorovich Stravinsky.

For a variety of reasons, the works at issue, which are foreign and produced decades ago, became part of the public domain in the United States but were still copyrighted overseas. In 1994, Congress adopted legislation to move the works back into copyright, so U.S. policy would comport with an international copyright treaty known as the Berne Convention.

In dissent, Justices Stephen Breyer and Samuel Alito said the legislation goes against the theory of copyright and “does not encourage anyone to produce a single new work.” Copyright, they noted, was part of the Constitution to promote the arts and sciences.