Legally, even running a program is making a copy (from disk to RAM): Yes, that is why 17 USC § 117 provides that making a transitory copy necessary to run the

Legally, even running a program is making a copy (from disk to RAM): Yes, that is why 17 USC § 117 provides that making a transitory copy necessary to run the program (such as a RAM copy), or an archival copy of the data needed to run the program, are both explicitly not violations of copyright. I think the question is whether the license YouTube implicitly provides to copy so one can stream also extends to downloading to a file. Probably not. It does not. Youtube does not explicitly, or implicitly, provide the user a license of any type. Youtube has licensed the right to provide a temporary copy of a video to a user. Why that should be youtube-dl's fault is yet another question, of course. It normally wouldn't be...except that some idiot decided to include unit tests to make sure that youtube-dl could be used to download music videos covered by RIAA licenses. That basically makes the RIAA's case, especially since youtube-dl must be regularly updated to handle Google's countermeasures.