The Nazis invented them. And they're in 90% of US kitchens but are banned in Russia. There's a really good rundown here from Mercola on the hazards of using microwaves. Leaked radiation affects our hearts, causing changes in heart rate and in heart rate variability. And of course we're getting similar radiation from cell phone towers, which frankly surround my current home and tower above the school building where I now sit. I seem to always have a microwave, but not because I ever buy one. Everywhere I go somebody buys one for my kitchen and then leaves it behind.