Here is a Cultural Literacy worksheet on the noun cause celebre. It means, as I am sure you know, “a legal case that excites widespread interest” and “a notorious person, thing, incident, or episode.”
This Gallicism isn’t exactly the most commonly used word in the the language, but educated people do use it. I’ll hazard a guess that one wouldn’t have far to look in major metropolitan newspapers or literary magazines like The Atlantic, Harpers, or The New Yorker to see this word in action. If nothing else, when children and adolescents make foolish choices, as the often do, this is the right word to describe them, especially in its latter sense.
If you find typos in this document, I would appreciate a notification. And, as always, if you find this material useful in your practice, I would be grateful to hear what you think of it. I seek your peer review.