Fun fact: during WWII, the British figured out a way to jam German radar by dropping bales of metal-coated plastic strips (called “chaff” or “Window”), but they held off on using it for more than a year because they didn’t want the Germans to figure out the secret and start using the same trick on their radar. Meanwhile, the Germans had also figured out this technique, but they also held out on using it because they didn’t want the British to get it.