This seems like the perfect way to address ads. If sites must be accessible and sites must clearly separate ads from non-ads then any attempt to obfuscate this will be futile if a working screen reader is the bar.

Has this been tried anywhere in a court?

I think it would be deemed inaccessible in a court of law if there was content you could not read, or you could not navigate between content and submit your own etc. but identifying content as an ad would probably not make it through the courts (especially not if some company like FB had the resources to fight it all the way, at least in the U.S)

Ad blockers were identifying Facebook content as ads by looking for the text "sponsored". For a while, Facebook was fighting this by scrambling that text in ways that would definitely have tripped up a screen reader (e.g. inserting extra hidden letters, reordering letters, etc).

they could also have put the sponsored message into an aria hidden div then the screen readers would be safe. Not difficult to separate out things that mess up automated solutions and screen readers from each other.

that would defeat the purpose of the obfuscation, as whatever screen reader can easily read so can userscript.

first off I suppose there can be lots of different places where aria-hidden would be used. So it might be really silly for userscript to strip out aria-hidden areas.

So then you use aria-hidden on your area with the obfuscated Sponsored text in it. Userscript still needs to handle it just as much as before, and the screen reader is free from dealing with it.

at any rate there is no real connection between these two technologies and if FB wanted to keep something from screen readers but still force userscripts to have to work to figure out what to do about them there would be thousands of ways to make that the case.

So if you're using an accessibility tool, you're not allowed to know which content is sponsored?

you would of course have to take it to court to have the court decide that yes, that was part of the definition of accessibility, I do not think that is part of any of the WAI or WCAG definitions although it would a good idea to ask for it, in fact I guess I will raise the issue later today on a mailing list.

But if you took it to court, in the U.S, if it went all the way to Supreme Court I have hard time believing it would not be denied. So effectively, they are not obligated to let you know which is which.

on edit: in initial discussion it was said " 1.1.1 Non-text Content, or 1.3.1 Info and Relationships." https://www.w3.org/WAI/WCAG21/Understanding/info-and-relatio... might be used as an argument that unidentifiable Ad content would be non-accessible https://www.w3.org/WAI/WCAG21/Understanding/info-and-relatio...