Any work anyone creates gives them Copy Right over it. But this is not absolute. There are significant "fair use" rights, uses which no one may legally object to. It seems there's a lack of legal clarity about what exactly constitutes fair use (anyone got good references on this?), so let's be diligent about citing sources and getting permission.
If we are going to allow any third-party material under claim of fair use, and do some kind of free/open license, we probably want to include language somewhere that makes it clear to any copiers that they are responsible for determining what counts as fair use - i.e., our use here of a third party work may count as fair use, but the use some copier might make of it may not.
From http://www.law.cornell.edu/uscode/17/107.shtml :
...the fair use of a copyrighted work ... for purposes such as criticism, comment, news reporting, teaching (including multiple copies for classroom use), scholarship, or research, is not an infringement of copyright. In determining whether the use made of a work in any particular case is a fair use the factors to be considered shall include -
(1) the purpose and character of the use, including whether such use is of a commercial nature or is for nonprofit educational purposes;
(2) the nature of the copyrighted work;
(3) the amount and substantiality of the portion used in relation to the copyrighted work as a whole; and
(4) the effect of the use upon the potential market for or value of the copyrighted work.
The fact that a work is unpublished shall not itself bar a finding of fair use if such finding is made upon consideration of all the above factors
(Just to complicate matters, we're talking about United States law here, and it's different - drastically so - in other jurisdictions -- sigh)
