US CODE, TITLE 17 > CHAPTER 1 > § 107 § 107. Limitations on exclusive rights
One of the rights accorded to the owner of copyright is the right to reproduce or to authorize others to reproduce the work in copies or phonorecords. This right is subject to certain limitations found in sections 107 through 118 of the copyright law ( title 17, U. S. Code). One of the more mportant limitations is the doctrine of “fair use.” The doctrine of fair use has developed through a substantial number of court decisions over the years and has been codified in section 107 of the copyright law. Section 107 contains a list of the various purposes for which the reproduction of a particular work may be considered fair, such as criticism comment, news reporting, teaching, scholarship, and research. Section 107 also sets out four factors to be considered in determining whether or
Re "FAIR USE" : "...means specified by(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..."
http://www.law.cornell.edu/uscode/html/uscode17/usc_sec_17_00000107----000-.html
