The ADA itself holds different organizations to more/less stringent standards based on a host of factors, government funding being a major one. Government agencies themselves are usually held to the most severe standards. That said, while ADA has adopted WCAG as the defacto standard, from what I’ve seen it appears they’re going with AA compliance as the most reliable one. That said, we’ve done work with some organizations who’ve chosen to comply with AAA in an effort to be as buttoned up as possible from an accessibility and experiential perspective. We’ve also worked with some who have tighter budgers and aim for level A compliance and have a more “react and repair” mindset when they discover anything in their site that is giving someone hardship from an accessibilirt standpoint.
Blind people, those with low vision, and people with other disabilities that affect their ability to read a computer display often use different technologies so they can access the information displayed on a webpage. Two commonly used technologies are screen readers and refreshable Braille displays. As discussed above, a screen reader is a computer program that speaks the text that appears on the computer display, beginning in the top-left corner. A refreshable Braille display is an electronic device that translates text into Braille characters that can be read by touch. These assistive technologies read text. They cannot translate images into speech or Braille, even if words appear in the images. For example, these technologies cannot interpret a photograph of a stop sign, even if the word “stop” appears in the image.

Case law has been the most helpful in illuminating the implications of the ADA for websites.There have been lawsuits involving companies like Expedia,, Southwest Airlines, and Target as defendants and primarily featuring accessibility organizations as plaintiffs. These cases had mixed results, but each helped clarify the ADA's jurisdiction on the web. 
If you return your availability by room type your our online booking engine must also display and hold accessible rooms only for people with disabilities until all other rooms have been booked. (Rule becomes effective March 15, 2012.)  If you return your availability by individual units you do NOT have to hold ADA rooms back until all other units have been reserved.  However, all other ADA regulations do apply (ADA room descriptions, using a booking engine that is ADA compliant, and making your website ADA accessible).

Recent years have seen an uptick in federal lawsuits filed against businesses and governments, alleging that their website violates the ADA by being insufficiently accessible to people with disabilities. In 2017, there were at least 814 such lawsuits against organizations in a variety of industries, from banks and credit unions to restaurants and e-commerce websites. The defendants include small businesses as well as major corporations such as Nike, Burger King, and the Hershey Company.