Below is the beginning of a paper on this topic.  The entire text is at
http://www.rit.edu/~easi/law/weblaw1.htm
and a number of other legal documents about information technology and
disabilities is at the same site:
http://www.rit.edu/~easi

Norman Coombs Chair of EASI

       Applying the ADA to the Internet: A Web Accessibility Standard
                         by Cynthia D. Waddell, JD
                 ADA Coordinator, City of San Jose, CA USA

   Although it may seem that the World Wide Web has been like the Wild,
   Wild, West --where there are no laws and each frontier web site is on
   its own, there are significant legal and practical reasons for
   ensuring web accessibility. By web accessibility I am referring to the
   design of a webpage that embraces the requirements of Universal Design
   in order to ensure that all users can access the information on the
   page:

     Universal Design calls for the development of information systems
     flexible enough to accommodate the needs of the broadest range of
     users of computers and telecommunications equipment, regardless of
     age or disability.
. . .

   Unless a web site is designed in an accessible format, significant
   populations will be locked out as the World Wide Web rapidly advances
   from a text-based communication format to a robust, graphical format
   embracing audio and video clip tools.

   Yet, the benefits of accessible web design extend beyond the community
   of people with disabilities and an aging population since it enables
   low technology to access high technology. There are substantial
   business incentives for technology transfer in underdeveloped
   countries and for populations who do not have the "state of the art"
   technology. Accessible web design features enable CD technology and
   videotapes to be archived with word search capabilities due to text
   captioning. Even people who are illiterate can access the Internet
   since screenreaders can audibly read text out loud from accessible
   webpages.

   As the capital of Silicon Valley, the City of San Jose is proud to be
   a national leader in web accessibility implementation for local
   government. This article briefly discusses specific legal requirements
   for accessible web design and how the City of San Jose developed and
   implemented a minimal web accessibility standard that is now supported
   by the first draft international protocol for web accessibility. In a
   nutshell, public policy and legal compliance requires the removal of
   barriers to effective communication and commerce. By accommodating
   members of our diverse community, government can play a catalytic role
   in promoting a sustainable community.

  I. United States Department of Justice Policy Ruling, 9/9/96: ADA
  Accessibility Requirements Apply to Internet Web Pages 10 NDLR 240

   The Americans with Disabilities Act (ADA) requires covered entities to
   furnish appropriate auxiliary aids and services where necessary to
   ensure effective communication with individuals with disabilities,
   unless doing so would result in a fundamental alteration to the
   program or service or in an undue burden. See 28 C.F.R. 36.303; 28
   C.F.R. 35.160. Auxiliary aids include taped texts, Brailled materials,
   large print materials, captioning and other methods of making audio
   and visual media available to people with disabilities.