What's fair use?
“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.”