Everybody is talking about “illegal copying” (most often in propagandist terms like “stealing” or “piracy”), but nobody of the opposite: Taking a work in public domain and slapping your copyright-notice over it; something which very much borders on plagiarism. And of course asserting to have a copyright on something which you are not entitled to is also a violation of copyright.
The very funny thing is, there is a repository of thousands of books whose copyright is violated this way. It’s http://books.google.com. Nowhere else, such a mass of works wrongly tagged “copyrighted material” can be found.