Some people seem be confused about copyright and public domain, thinking things like:
- I used some public domain code in my program, so I have to release it as public domain as well
- I should be able to take some public domain code, add my own copyright to it and then prevent anyone else from using the public domain version
- I need a new law passed so that I can copyright this list of facts I compiled.
These are all wrong. Public domain isn't a copyright license like the GPL - it's just the absence of copyright, meaning that you can do what you like with it.
There's nothing stopping anyone from taking copyright-expired works of arts or lists of facts and copyrighting them, but such a copyright would be completely useless because it couldn't be enforced - if you sue someone for violating your copyright on that work they have an iron-clad defence - they can just say "my work is based on the public domain version, not your version" (in the case of copyright-expired works) or "I compiled my own list of facts which happens to be the same as yours because both are based on the same reality" (in the case of the phone book example) and you would not be able to prove that they had referred to your copyrighted work.
No new law is necessary because there's an easy workaround - just change something slightly to make it a new creative work - add a fake name to your phone book or change a few words in that old story. Then not only do you have a perfectly good legal case against anyone who copies your work, you also have a way to prove it (their copy will also have your changes). And you won't be "removing" anything from the public domain to boot. Sure you probably can't make much money by taking public domain works, changing something and then releasing a copyrighted version, but that's seems quite reasonable to me because you haven't actually contributed much (if anything).
I understand that map makers have used this technique in the past - changing the position of roads slightly or adding features to the map that don't exist in reality in order to make their maps copyrightable "creative works" and to enable them to track down counterfeiters.