Seems punitive to me, rather than 'fair'. US copyright law has no jurisdiction the same as German copyright law, other than by coincidence of geography/volunteer base. I think Project Gutenberg is doing the best thing it can for itself. I associate the project with doing the best thing it can for people.
In general, we're going to run into increasing numbers of cases like this.
This is incredible. I followed this link down into the Margolus-Levitin theorem, which puts a physical limit to how much computation (entropy?) you can produce with a single joule of energy (6 x 10^33 operations/second).
It seems that at some point the unit for powering computers would then have to be matter, since there's such an incredible amount of energy stored per newton.
In general, we're going to run into increasing numbers of cases like this.