Now when you go to their site, it reads:
Repository unavailable due to DMCA takedown.
This repository is currently disabled due to a DMCA takedown notice. We have disabled public access to the repository. The notice has been publicly posted.
If you are the repository owner, and you believe that your repository was disabled as a result of mistake or misidentification, you have the right to file a counter notice and have the repository reinstated. Our help articles provide more details on our DMCA takedown policy and how to file a counter notice. If you have any questions about the process or the risks in filing a counter notice, we suggest that you consult with a lawyer.
Also at 9to5Google
[2020-10-25 01:01:09 UTC: Updated title to more accurately reflect notice was given to GitHub, not to youtube-dl. --martyb]
(Score: 0) by Anonymous Coward on Saturday October 24 2020, @11:04PM
And that is where the real power of this DMCA notice comes in. If you read it, they also characterize the tool as an anti-circumvention tool in addition for one to enable piracy. The reason is the interpreters. The tool isn't accessing the videos in the intended manner. Instead, it is circumventing it using the interpretation engines and arguable circumventing the protections put in place to protect the videos. True, it is different from the precedents of DeCSS and similar that use stolen keys and libdvdcss and similar that brutes keys, in that it is evaluating JS provided to it using key data provided to it in a way analogous but not identical to the intended user agent. The real question is whether that is legally close enough. And I expect the EFF to chime in eventually on that question with a better analysis.