The Americans with Disabilities Act (ADA) was first passed in 1990. Twenty years later, the US Department of Justice released an update called the 2010 ADA Standards for Accessible Design. These standards cover the design of physical spaces and have been interpreted to include web locations as well, so it can be difficult for the would-be accessible website designer to use them.
An example is Patagonia Works, Inc. which had a complaint for a permanent injunction filed against it in the United States District Court stating, Under Section 302(b)(1) of Title III of the ADA, it is unlawful discrimination to deny individuals with disabilities an opportunity to participate in or benefit from the goods, services, facilities, privileges, advantages or accommodations, which is equal to the opportunities afforded to other individuals. 42 U.S.C. 12182 (b)(1)(A)(ii). Below is a summary of what the lawyers asked the court for.
The Federal Communications Commission (FCC) enforces regulations covering telecommunication services. Title IV of the ADA covers telephone and television access for people with hearing and speech disabilities. It requires telephone and Internet companies to provide a nationwide system of telecommunications relay services that allow people with hearing and speech disabilities to communicate over the telephone.