"Fair use" is a doctrine in copyright law that can be used as a defense to unlicensed use of a copyrighted work provided certain conditions are met. Keep in mind that the application of the fair use doctrine does not give you the right to use copyrighted materials, but rather a defense that may be raised once you have been sued for copyright infringement. Although the doctrine of fair use is broad, there are many limitations to common notions of fair use.
There are no guarantees when it comes to defining what actions may constitute fair use, but courts have developed a set of factors to be analyzed when employing the fair use defense. The factors courts look to include the purpose and character of the use, nature of the copyrighted work, amount of original work used, and effect of the use upon the potential market for or value of the original work. Generally, nonprofit and scholarly uses are most likely to be construed as fair use.
Parody Versus Satire
Courts have held that parody may be considered fair use when an artist uses some of the elements of a copyrighted work to create a new work commenting on the original work. In order to be considered parody, the new work must be transformative in nature so as to have critical bearing on the substance and style of the original work. Alternatively, if the new work is merely a satire of the original work, meaning the new work uses the original work to comment on or criticize something other than the original work, such use may be copyright infringement. The distinction is subtle, but in order for a parody to be considered fair use it must comment on or criticize the original work it is referencing.
The DMCA, or Digital Millennium Copyright Act, sets forth rules against and penalties for the circumvention of access controls placed on digital copyrighted goods to prevent copying or other unauthorized use. The anti-circumvention provisions of the DMCA create a unique situation as it relates to fair use because fair use generally allows a defense for behaviors that would otherwise be considered copyright infringement. Because of the current unclear status of the law, it is possible to be found guilty of violating the DMCA despite having a fair use defense to the underlying copyright infringement resulting from violation of DMCA anti-circumvention measures.
Copyright law allows individuals to make one copy of digital software or digital goods for the purpose of backing up the materials in case the originals are lost. This backup copy is a form of fair use that permits limited copying of the copyrighted work. Although you may be permitted to make one backup copy, you are not permitted to distribute this copy or make additional copies for personal reasons. Additionally, if you transfer or sell the original copyrighted work you will need to destroy your backup copy in order to comply with fair use principles.