CopyLaw.com has an article on New Rules for Using Pubic Domain Materials, written by Attorney Lloyd J. Jassin. Copyright laws, and public domain usage is confusing and ever changing.
Public Domain are works that are free to use. Nasa has a website where you can use their photographs of stars, planets, nebulas, and the sort. Judicial opinions, legislative enactments, official documents, and so on, are free to use. It is difficult to tell what is in the public domain without doing extensive research. Any work created before 1922 is in the public domain. Anything created in 1923 or after will not be in the public domain until 2019. There are however several works that were released into public domain because the creator of the work did not seek to renew their copyright license, or in certain years, did not place the copyright symbol in the exact spot that it was required too.
Copy right laws have changed over the years, but the one change that is currently in place is works created on or after January 1, 1978. This copyright law covers the work for the life of the author, plus 70 years. If there are one or more creators, the copyright will last 70 years beyond the last creator’s death.
With that said, with technology came a new enlightenment for the public domain content. There are now apps to download onto a smartphone so anyone can download a book that is in the public domain, there are thousands of old classic books for free usage. There are numerous paintings that the likeness can be played with because of it’s creation date being before 1923.
TV’s with HDMI cables can block you from copying movies and selling them on the corner, or the internet. I understand BlueRay movies are not copy-able either. Film production company’s enjoy that feature. Some BlueRay movies will offer a free digital copy to download onto a computer, iPad, or smartphone, once you have purchased the movie and open the box.
Finally, I do not know if the copyright laws are sufficiently up-to-date, but I can say it is awfully confusing. I would think there must be a better way to protect the copyright holder’s works, without confusing the public on whether they can use a creation or not.