Oracle has a pretty strong case against Google.
To address the issue of fair use and if APIs can be copyrightable:
1. Judge Alsup told Google's counsel that Google had to address the Johnson Controls decision with a view to the Java APIs.
On October 3, 1989, the Ninth Circuit held the following in Johnson Controls v. Phoenix Control Systems:
"A computer program is made up of several different components, including the source and object code, the structure, sequence and/or organization of the program, the user interface, and the function, or purpose, of the program. Whether a particular component of a program is protected by a copyright depends on whether it qualifies as an 'expression' of an idea, rather than the idea itself."
On to paragraph 13:
"Here, the district court found that the structure, sequence and organization of the JC-5000S was expression, and thus subject to protection. [...] This issue will no doubt be revisited at trial, but at this stage of the proceedings we cannot say that the district court clearly erred."
http://law.justia.com/cases/federal/appellate-courts/F2/886/...
http://www.fosspatents.com/2012/05/oracle-v-google-cant-make...
2. the fair use of a copyrighted work, including such use by reproduction in copies or phonorecords or by any other means specified by that section, 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: the purpose and character of the use, including whether such use is of a commercial nature or is for nonprofit educational purposes;