The phrase is French slang built around caca, a childish word for poop, aimed directly at the American pop group the Black Eyed Peas. Because the target is so specific and random, the clip circulates online less as serious music criticism and more as an absurd reaction sound that anyone can reuse. It has spread through short meme edits, soundboards and chat shares where a quick spoken dismissal is funnier than a long explanation, and its brevity keeps it easy to drop into unrelated jokes.