I think the reason the MR library is in the lead is because it's free and I do feel that it will lead to copyright infringement. I do expect that is a book is only public domain in life+50 countries that people in life+70 countries will download. I also think that books that are only public domain in the USA will be downloaded outside the USA.
This is a category that will lead to copyright infringement. So the only way to avoid this is to only allow books that are public domain world wide and not only parts of the world.