It hit me today to ponder if the current law for what's public domain could be changed. Wonder if that's something the GNU lawyer would answer for me... If Mickey can get an extension, I wonder if there's anything to stop Congress from saying, "We're revoking the public domain provision and, 1984-style, retroactively changing what's under copyright from before 1923"? Register current, pre-change uses, have the law go into effect two years after passage to give ample time to get those uses (and new ones) in the books, etc etc.

And here's one example (using Disney again, no less) of how the envelope has already been pushed back at least once...

from: A Possible Exception for the Pre-1923 Public Domain Rule
US law regarding duration of copyrights for works published before 1978 states that copyright runs for a fixed period of time "from the date it was originally secured". In general, publication has often been considered the time at which either copyright was secured or a work fell into the public domain. However, in Twin Books v. Walt Disney Co. (83 F. 3d 1162), the Ninth Circuit held that the copyright to Bambi had not actually been secured until 1926, even though the work was first published in 1923, in Germany. (See the text of the decision, courtesy In the court's opinion, Bambi's US copyright commenced at the time it was first published with a copyright notice recognized by US law.

We may have separated church and state, but all that's done is push the worship out of the church and into the Federal Reserve and Wall Street. The "potential" of America scares me sometimes.