I do not understand how some people/entity interprets Copyright and Public Domain materials. The scenario is like this: A vintage crochet pattern that is now on public domain is scanned by someone (or a business/charitable entity). After scanning, this person or entity claims copyright to the said pattern just because the pattern was compiled in a book that contains all the scanned public domain patterns. The way I understand it, is that, a published written pattern is either public domain or copyrighted and cannot be both. If this scenario were true for a pattern that was mass produced and gone to public domain, there could be several copyright claimants for the same pattern. All they have to do is scan the documents and compile it along with other scanned public domain patterns and tell the public they own the copyright. As far as I know, Only one person or entity can claim copyright to the same published material or book.
I found an interesting article and discussion
here Although the article is about a photo, same logic should be applied on written materials as well.
Public Domain materials are supposed to be used by anyone and everyone in "any way they want to use it", . Sadly, some people and entity interprets "any way they want to use it", to mean, they can use it for their benefit or profit alone and hinder the public from having access to the public domain items. For more information regarding copyrights and public domain, I found
this
and this
After reading the above articles, my conclusion is that no one has the right to claim copyright on materials that are in the public domain. These materials should remain accessible to the public and use for the benefit of the public and not individual or private enterprise.