copy right fair use act
 
 TITLE 17 > CHAPTER 1 > § 107
Release date: 2004-04-30   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 includeâ€?nbsp; 
(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The fact that a work is unpublished shall not itself bar a finding of fair use if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.