| yt-dl exists not just for youtube, it allows users to access audio and video streams from many different websites without the overhead of a full featured web browser. But in the case of youtube, it exists to automate what can trivially be done by hand using the inspector. Seriously, yt-dl really does just selectively run some javascript which gives it the video URL. I disagree that "effectively" means "in effect", it's the first time I've heard of this and in past court cases regarding such protection measures, the plaintiff had to prove that the measure was effective (not trivially bypassed by an unskilled average user by accident as I think could be argued in this case). Regarding your claim that I am "pretending" that yt-dl simply does what YouTube does: When I go to the inspector and find the URL for the video and audio streams, without prior knowledge that youtube is using some kind of "rolling cipher" I would have no idea that there was some kind of protection in use. I can access the video stream of a youtube video using just my mouse, I don't have to run any functions or find any decryption functions. You should try it. It's hard to argue that there is a protection mechanism in place if someone could by accident discover the video data if they were a curious user who started playing around with the inspector console. Finally, to address your implication that the tool is designed to unlawfully acquire content from youtube. I don't think the tool is intended for that purpose, at least not the way it is presented. I think it's important to distinguish between "downloading with intent to keep" and "downloading with intent to temporarily access". I'm not sure if such a distinction is ever made in the courts but it should be considering the former may be illegal depending on whether you asked the copyright holder if you can do it and the latter is literally what your web browser does. 99% of the time I use youtube-dl (which is also the way it gets used by programs like mpv or the kodi youtube plugin), I use it to access and temporarily view a video. I may be on a machine where having a full fledged web browser would be impossible because of performance reasons or whatever. Or I just don't like the youtube viewer and want more control over the playback. The project also codifies in multiple places the intention that it is not designed for illegal use. Extractors which bypass DRM or access control measures are not accepted. If you look at the implementation of youtube-dl's youtube extractor (please do, the code isn't that complex) it is easy to claim that: youtube-dl is simply a very heavily stripped down web browser which is intended simply to provide the ability to view videos and audio streams on websites with minimal overhead without any intent to circumvent any protection schemes. As a final note: youtube does have DRM protected videos which use some kind of encryption, these do not work with youtube-dl, I tried (and I paid for the video not knowing that I would be stuck with it being encrypted unless I had EME enabled, in a last ditch effort to watch it I tried youtube-dl but it had the same problem, I got a refund). |