During WWII, the British…

During WWII, the British launched nearly 100,000 weather balloons trailing long metal wires toward occupied Europe, causing power outages when they shorted out power lines and causing at least one German power station to burn down. The US military “rediscovered” this during training operations in the San Diego area a few decades ago when metallic radar cloaking chaff accidentally drifted into a substation causing a widespread power outage. This led to development of ordnance that released carbon fibers for the same effect. It was used during the Iraq war.