The line comes from a Thai-language clip that circulated online as a dramatic confrontation meme. The uploaded file's own metadata points to a Thai news-style viral video built around a heated exchange, which is where this one-second 'who are you' appears to originate. Since then the isolated line has taken on a second life as a reaction sound in short-form edits, where its blunt, accusatory delivery fits call-outs and surprise reveals. It stays popular because the phrasing is instantly reusable, even for viewers who don't speak Thai.