17 U.S.C. Section 107 provides in part:
Notwithstanding the provisions of sections 106 and 106A, 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:
(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.