I've had it by accident. When I was a kid I loved a certain brand of frozen hamburger. I used to eat lots of it. One day I was watching TV while eating those burgers and the local news announcer said the company executives of that frozen hamburger company had been arrested for using horsemeat in their burgers. My mother screamed at me right then to put down my burger. However, I continued eating it. My only regret was that those burgers were no longer available in supermarkets.
There was actually a little hamburger joint here in Fresno many years ago called "Judy Judy Judy's"..any old time Fresnans remember this place? Turned out the meat in the burgers were horse meat which was why they only sold for a dime. You could tell it wasn't beef, it was very sweet tasting.