Its not just modern US, I have a book here that I was reading last night that was printed and distributed in 1898 on Darkroom formulation and such the also mentioned copyright issues, so this is not a new thing, as is it is not anywhere in the world, copyright extends a long ways back and in fact, I watched a show on the Rossetta Stone that made a statement about the british sueing the french in 1822 over the ownership of the copyright on the stone, and if anything has historical value it is the Rosetta Stone!