Call me anon
There are a lot of music album videos on Youtube. Programs called "downloaders" allow one to convert the stream provided by youtube to .MP4 or .FLV. IANAL, but the crystallization of a stream into a file may have legal implications in some jurisdictions. But since that transformation takes place via a program on one's own computer, away from prying eyes, many may feel at ease with the consequences.
The video portion of many of these music albums is simply a single image. This suggests, might the user strip away the video and remain with a pure-audio format such as .MP3 or even .FLAC? For later listening-only pleasure. It's an old concept, and some computers may have de-muxing or ripping software already installed. But I see that the standard way to obtain an MP3 from a video is not on your own computer. There are dozens of on-line converters. You paste the youtube video URL then moments later download the music. There are even sites which tell you how to do this. How late I am to the game is evidenced by this never having entered my mind, and it's now almost 2017. But the bell started going ding-ding-ding in that mind. So a third-party has your IP address and full knowledge of the music album which you, ah, commandeered, from youtube. Isn't that asking for copyright troll trouble? Are they saving up all the data for one almighty pain purge? Trolls are trolls, after all. And the method used is far simpler than the ones in this story.
Might a VPN help, or at least make you a more complex target? If there were an inkling of possible pain, users would do what they've always done, which is to rip the files on their own computer. Purely for education, I tried doing an .MP4 to .MP3 conversion in VLC 2.2.4 over Win7. It didn't fully work. But foobar 2000 did. You don't even need specialized ripping software. A free program that you might already have on your computer to play music will suffice. Although the first iteration is more complex than ^find ^copy ^paste, subsequent rips should be almost that simple.