The doctine of “fair use" in U.S. Copyright law lists of the various purposes for which the reproduction of a particular work may be considered “fair,” such as criticism, comment, news reporting, teaching, scholarship, and research.
These uses are powerful, but not unrestricted. The guidelines below will help explain the restrictions on fair use. Four factors must be considered when evaluating Fair Use.
1. PURPOSE: The purpose and character of the use, including whether such use is of a commercial nature or is for nonprofit educational purposes;
2. NATURE: The nature of the copyrighted work;
- The balance tips in favor of fair use for published, factual, nonfiction material; the reverse is true for unpublished*or highly creative work (music).
3. AMOUNT: The amount and substantiality of the portion used in relation to the copyrighted work as a whole;
- The balance tips in favor of fair use when a portion is small, not central to the work, and tailored to the exact educational purpose intended.
- The less you take, the more likely that your copying will be excused as a fair use. However, even if you take a small portion of a work, your copying will not be a fair use if the portion taken is the “heart” of the work. In other words, you are more likely to run into problems if you take the most memorable aspect of a work.
4. MARKET: The effect of the use upon the potential market for or value of the copyrighted work.
- The balance tips in favor of fair use when a legal copy is owned and use doesn't significantly impair sales.
- Another important fair use factor is whether your use deprives the copyright owner of income or undermines a new or potential market. Depriving a copyright owner of income is very likely to trigger a lawsuit. This is true even if you are not competing directly with the original work. -
See more at: http://fairuse.stanford.edu/overview/fair-use/four-factors/#sthash.nMl8aqMF.dpuf