Fair use permits the reproduction of creative works for criticism, comment, news reporting, scholarship, research, teaching, and parody.
Your responsibility is to exercise due diligence, make an informed decision and try your best. Making a fair use determination is a balancing test and requires weighing four factors:
- The purpose and character of the use – favors non-profit educational use
- The nature of the work – creative works tend to be more protected
- The amount and substantiality of the selection in relation to the whole work – includes whether or not you are using the “heart of the work”
- The effect of the use upon the potential market for the work – favors no market harm
Further, works that are transformative are more likely to be fair use. Stanford provides a succinct overview of transformation, which is heavily exercised for parody. Google Books was also declared a transformative fair use.