I posted a video where I was giving a talk about improvisation and this included a snippet of a Keith Jarrett performance, and I got one of those warnings. Makes me wonder if some automated thing searches for matching sounds in anything for copyrighted material. But yeah, it is kind of ridiculous. How is giving a talk about something even remotely close to infringing copyright?
I think it's great that youtube is making a conscientious effort to protect artists' livelihoods.
Copyright law as it exists today, at least in the U.S., is the best chance artists have ever had in history to make it slightly more than theoretically possible to actually make a living from one's work.