Fair Use considers
- the purpose and character of the use, including whether
such use is of a commercial nature or is for nonprofit
- educational purposes;
- the nature of the copyrighted work;
- the amount and substantiality of the portion used in
relation to the copyrighted work as a whole; and
- the effect of the use upon the potential market for
or value of the copyrighted work.
Fair use is not a constitutional right ... it's given
by congress.