Actually YT allows hiding movies from public list, so the content wouldn't be shared context free. It would be only available to people, who you want to share it with. But does it change anything for Youtube? Btw, I'm surprised with your being surprised, as Sony Ericsson has been including their TrackID app for few good years now. Surely same process applied to video is far more complex, but let's not compare Gracenote (acquired by Sony) with Youtube.