Copyright can't control what you do with code, on your own computer. Disassemble Windows if you want to. Nor, in theory, can it control what you do with music i

Copyright can't control what you do with code, on your own computer. Disassemble Windows if you want to. Nor, in theory, can it control what you do with music in the privacy of your own home. Block YouTube ads if you want to. It can control your right to redistribute. Hence youtube-dl is legal, but a website that runs youtube-dl and gives you the result isn't.