An old music friend of mine was recording a bunch of found sounds and making a noise project. He never sold any of his music (that no one would buy it notwithstanding). One of those sounds was background muppet noises on tv while his friends were talking over it. He sent a nice letter explaining that he was making this art project and asked if they’d let him use the clip. A few days later he got the full on cease and desist twelve page manifesto of go fuck yourself.
I get copyrights and trademarks and all, but fuck Jim Henson.