slew writes: Ironically, today of all days, the US Supreme court decided that congress was within its authority to grant new and/or restored copyright protection to preexisting works to comply with copyright treaties. This effectively takes works mainly authored between 1923 and 1989 that had been in the public domain, out of the public domain. This is in a majority opinion written by Justice Ginsburg which can be read here
In a disenting opinion authored by Justices Breyer and Alito voices the view that this "does not serve copyright's traditional public ends, namely the creation of monetary awards that motivate the create activity of authors", but only grants its restored copyrights only to works already produced.
The original suite was that the way that congress complied with the copyright treaty was overbroad (e.g., the Berne convention allowed restricted terms for works of restored copyrights to account for the disruption it might cause, but congress gave blanket restoration for all works)