The EFF's claim (on behalf of the youtube_dl developers) is that youtube_dl is performing the same actions as a browser as far as accessing the video file and so should not be treated differently, even if its output is to disk and not to the screen.
Under DMCA then we've had a claim, and counter notice. Despite the phrasing of Github inviting and wanting a counter notice, ultimately they are not the arbiters of legality, so their part in the process is now done.
The RIAA now has to bring the youtube_dl developers to court if they plan to keep pushing their argument, at which point we'll have the RIAA lawyers vs EFF lawyers and an eventual legal decision (with potential appeals in the process).
It's not.
It may be treated differently under other parts of copyright law based on implied license or other theory, but the DMCA impact is on distributing, offering, etc. youtube-dl, not using it, insofar as it constitutes a circumvention tool under the DMCA.
> Because youtube-dl simply uses the "signature" code provided by YouTube in the same manner as any browser, rather than bypassing or avoiding it, it does not circumvent, and any alleged lack of authorization from YouTube or the RIAA is irrelevant.
[1] https://github.com/github/dmca/blob/master/2020/11/2020-11-1...
https://github.com/github/dmca/blob/master/2020/11/2020-11-1...