Belief in the power of the public domain is one of the main causes of intellectual property violations. Just because something is on the internet, does not mean you are free to use it. The term “public domain” does not mean anything accessible by the public. It’s a very complicated field of law dealing with expired (or otherwise invalid) copyrights. Fortunately, Berkley Law School has published a useful guide for determining public domain as it relates to copyright. I saw that with a caveat – it’s useful for attorneys, but everyone else may find it a bit overwhelming. It seems that even making it easy makes it look hard.
BerkleyLaw – Is it in the Public Domain? [pdf]