A married couple in South Korea bolted a speaker to their ceiling, aimed it at their noisy upstairs neighbor, and got convicted of stalking. In the autumn of 2021, a couple in Daejeon bought a bone-conduction woofer specifically marketed for inter-floor-noise revenge. They mounted it facing up, toward the unit above them, and over two months ran it at the woman upstairs roughly 10 times. The playlist included a 12-hour loop of footsteps and chair-scraping, and stretches of death metal. The upstairs neighbor was the person they believed had been stomping on their ceiling for months. But when police made an arrest, they arrested the couple downstairs. The Daejeon District Court convicted both under the Act on Punishment of Stalking Crimes, fined them 7 million won each, and ordered 40 hours of a stalking-treatment program. The husband appealed, betting a higher court would see a provoked man rather than a stalker. The appellate bench raised the penalty instead, converting his fine to six months in prison suspended for two years, writing that what he had done was no different from criminal assault. The woman upstairs, the original source of the noise, was never charged with anything. In December 2023, the Supreme Court made this asymmetry into precedent. The stalking act defines the crime as repeatedly making sound reach a specific person against their will in a way that causes anxiety or fear. A ceiling woofer fits perfectly: aimed at a known individual, deliberate, repeated. The original noise rarely fits, because it can be called daily living, because no one chose it as an attack. Two months of death metal aimed at a specific woman is unhinged, and the appellate court was not wrong to call it assault. But a revenge campaign leaves a trail the system can read: an order history, a saved YouTube search, a device bolted to a ceiling, a neighbor's recording. The original footsteps leave nothing the state will act on. The couple made themselves visible by doing something disturbing. The woman above them stayed invisible by doing nothing anyone would measure.