The RIAA just got GitHub to ban open source YouTube downloaders.
They don't want anyone to share this code:
mplayer $(echo -s "http://youtube.com/get_video.php?$(curl $youtube_url | sed -n "/watch_fullscreen/s;.*\(video_id.\+\)&title.*;\1;p")&fmt=22")
Woops.
https://github.com/github/dmca/blob/master/2020/10/2020-10-23-RIAA.md
$ curl -sL $youtube_url |grep watch_fullscreen
$
looks like there's no "watch_fullscreen" in the HTML. Oops.
And I didn't even pick a VEVO video - those have some extra obfuscation
@lrvick ... except running the curl|sed on a random youtube url gives me an empty result?
@lrvick @Saxxon or, you know, this: https://github.com/github/dmca/pull/8142
Server run by the main developers of the project 
It is not focused on any particular niche interest - everyone is welcome as long as you follow our code of conduct!
Note: this version probably doesn't work on most/all videos today after some more testing.
It is an iteration of one I wrote years ago:
https://commandlinefu.com/commands/view/1405/stream-youtube-url-directly-to-mplayer