I've used it to pull the audio off videos of live jazz performances, so I can run slow-down tools and play along to learn. I could do the same by recording the

I've used it to pull the audio off videos of live jazz performances, so I can run slow-down tools and play along to learn. I could do the same by recording the audio out of my laptop. That type of thing is not the majority use case for youtube-dl, but for any type of digital media there are plenty of individual, educational use cases that do not involve "pirate" activity (i.e. further distribution). Whether or not that's officially ok or not, I'd assert it is morally ok. As an aside, if YouTube is the only or canonical source for some material, getting it from the distribution channel (YT) and getting any access to the media in question are now one and the same problem. But let's not get confused about the value YouTube is providing - they are just a distributor, not a creative originator.