You may want to contact a lawyer about suing them for asking, but I'm not sure how that works.
The above applies to the US. If you are in a different country then you need to check your local laws.
One of the "questions" on their apply for job form is
TL;DR
Optional field is REQUIRED and only option is "Yes"
"At Thoughtworks, we are intentional about making technology a better place for all. We know that the more diverse our backgrounds are, the more impactful solutions we build for our clients. We foster an inclusive community and focus on creating a balanced workforce reflective of the society we live in.To help us achieve this balance, we encourage you to answer these demographic questions. We collect this data to understand who we are reaching (and who we’re not) so we can do better at connecting with a truly diverse group of potential Thoughtworkers. Our recruiting teams will only see the data collected here on an aggregated level, consistent with our Data Privacy Policy. Responding to the questions is completely voluntary and anonymous. Declining to respond will not impact your standing in the recruiting process."
The field is REQUIRED and the only option is "Yes"
It's the most bizarro thing I've ever seen, a single line text field.
Feeling kinda leet at the time I decided to take the plunge and cut and paste cover letter, CV, LinkedIn profile etc into this small field and let it burn.
Unsurprisingly I never got contact or received any confirmation or anything....
Why the hell would they even have that as an option?
(I am the %8 !!)
Example: https://www.thoughtworks.com/en-au/careers/jobs/4526889
Scroll down to 'Apply for this job' and click to activate JavaScript expanding form....bleaugh