The TEACH act is the first copyright legislation of special significance to educators since the Copyright Act of 1976 and its amendments. TEACH stands for "Technology, Education and Copyright Harmonization Act" and the act was signed into law on November 2, 2002. TEACH redefined "the terms and conditions on which accredited, nonprofit educational institutions throughout the U.S. may use copyright protected materials in distance education-including on websites and by other digital means--without permission from the copyright owner and without payment of royalties (Crews)."
-Source: Crews, Kenneth. Distance Education and the TEACH Act. American Library Association. 2006-2014. (linked below)
Some of the special copyright requirements of online distance learning are specifically addressed by the TEACH Act.
Linked below is an excellent, brief guide to the TEACH Act produced by the Copyright Clearance Center. It highlights the rights and responsibilities of educational institutions wishing to take advantage of provisions of the Act.
Two important requirements are that the materials used be part of "mediated instructional activities" and that the materials be limited to use by only those students enrolled in a specific class.