Hey Casey, this is one of the areas where things get a little weird because the W3 doesn’t actually have any say over the ADA guidelines, it is more than the ADA guidelines adopted the WCAG 2.0 guidelines as just that, a guideline to help. As far as I know, the tool you’ve linked to hasn’t been used in any judgements I’m aware of. Usually when it comes down to making a decision on if something is/isn’t compliant they have people use the actual PAWS tools and show what elements do/don’t work as intended or are otherwise inaccessible. Hope this helps!
Federal law isn't the only consideration for businesses. Additionally, each state interprets the law differently. Consider the case against Netflix in 2012. Lawsuits were brought in federal court in Massachusetts and California. Netflix was accused of violating the ADA by not offering "closed captioning" options for its Internet streamed movies. Illustrating the complexity of this issue, the courts reached completely opposite decisions. Massachusetts held that Netflix must comply with the ADA, while the California court found that Netflix did not fall under the ADA's definition of "public accommodation."
One example of a barrier would be a photograph of a Mayor on a town website with no text identifying it. Because screen readers cannot interpret images unless there is text associated with it, a blind person would have no way of knowing whether the image is an unidentified photo or logo, artwork, a link to another page, or something else. Simply adding a line of simple hidden computer code to label the photograph “Photograph of Mayor Jane Smith” will allow the blind user to make sense of the image.
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.