Our latest Freakonomics Radio podcast, "Boo...Who?", tackles the phenomenon of booing. Why do we do it? When and where (if ever) is it appropriate? While we focus mostly on modern examples, audiences have been voicing their displeasure for millennia. Tracing the boo back to its origins takes you to ancient Greece, and the Festival of Dionysia, when playwrights competed to determine whose tragedy was the best. Audience participation was considered a civic duty. At the Colosseum in Rome, booing, or the lack thereof, often determined whether a gladiator lived or died.
Hard to say exactly what a boo sounded like back then. Maybe more of a shout, a jeer, or a whistle, rather than the extended, cow-like booooooo we issue today. According to linguist Ben Zimmer, the first time the word "boo" appeared as an expression of dissatisfaction was in the diary of a British schoolboy in 1833. Zimmer wrote about it here. Below, we've compiled a list of some noteworthy boos. It is not remotely encyclopedic, and leans very heavily on very recent events. So feel free to supplement with more examples in the comments section.