Useful Web Resources on Copyright Law and Fair Use:


United States Copyright Office

Excerpt from http://www.copyright.gov/fls/fl102.html:  Section 107 of US Copyright Law contains a list 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. Section 107 also sets out four factors to be considered in determining whether or not a particular use is fair:

  1. the purpose and character of the use, including whether such use is of commercial nature or is for nonprofit educational purposes;
  2. the nature of the copyrighted work;
  3. 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.

The distinction between “fair use” and infringement may be unclear and not easily defined. There is no specific number of words, lines, or notes that may safely be taken without permission. Acknowledging the source of the copyrighted material does not substitute for obtaining permission.

Links:

The Copyright Laws and Fair Use (The University of Iowa Libraries)
Fair Use Guidelines for Educational Multimedia (Pennsylvania State University)
An Education in Copyright Law: A Primer for Cyberspace (Dr. Robert N. Diotalevi, Esq., LL.M.) 
The TEACH Act Toolkit (North Carolina State University)
Copyright and Multimedia Law for Web Builders and Multimedia Authors (University of Iowa Libraries)
Digital Millennium Copyright Act Summary (US Copyright Office)
DMCA - Exemption Procedures (University of Iowa)
Copyright and the University of Iowa