[pp.int.general] US Supreme court: Is granting retroactive copying monopoly legal or not?

[Pat Maechler aka Valio]

There is an upcoming court case in the US supreme court concerning
copying monopoly that will be one of the most important ones:
Can works that were already public domain be retroactively
"re-protected" by a legislative decision or not?
http://www.washingtonpost.com/politics/supreme-court-copyright-case-will-decide-fate-of-millions-of-once-public-works/2011/10/03/gIQAfX6LLL_story.html
http://www.scotusblog.com/case-files/cases/golan-v-holder/

-pat