17 U.S.C. §107 outlines the factors to be considered in Fair Use:

1. The purpose and character of the use, including whether such use is of a commercial nature or is it for non-profit educational purposes?

2. Nature of the copyrighted work.

3. The amount an 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.