Rick Anderson has published "NYPL Shows Academic Libraries What ‘Public Domain’ Means" in The Scholarly Kitchen.
Here's an excerpt:
In far too many libraries, public-domain documents and images are treated as if they were under copyright—and, even worse, in many cases the policies in question are written as if the holding libraries were themselves the copyright holders. Sometimes this is because the librarians who control access to those images genuinely don't understand copyright law: they believe that simply digitizing an image results in a copyrightable document (it doesn't), or that owning the physical item gives one legal say over how its intellectual content can be used (also untrue). The result is that in many academic libraries, intellectual content that the public has a right to access, copy, adapt, and generally reuse in any way we wish is being locked down and restricted by—ironically enough—librarians.