French authorities are investigating a case where someone allegedly used a hairdryer to manipulate a temperature sensor at Paris's Charles de Gaulle airport, allowing them to win roughly $34,000 in Polymarket weather bets when the readings spiked. The sensor sits unguarded on a public road near the runway, making it accessible to manipulation—Météo-France filed a formal complaint and relocated the sensor after detecting the irregularities. This incident exposes a major vulnerability in prediction markets that rely on publicly accessible real-world data points, and raises broader concerns about what could happen if someone used more sophisticated methods to rig bets on higher-stakes outcomes like geopolitical events or military conflicts.