https://github.com/github/dmca/search?q=HackerRank&type=
https://github.com/github/dmca/search?q=TheRayTracer
HackerRank/WorthIT didn't dispute the counternotice (AFAICT), but instead they re-filed the same DMCA notice again, four months later. I think the repo owner gave up at that point.
https://github.com/github/dmca/search?q=HackerRank&type=