There's a science fiction story, I don't remember the author or the title, where a man, an alien, visits Earth. He is from an advanced species, that can hide it's appearance to appear human. He's not a government representative, or a military scout- he's just a peddler, trying to sell his goods. He knows Earth is a banned planet- that you're not allowed to sell to humans, but he needs to make a living. And after all, he's only selling harmless toys.
His government's police catch up with him and arrest him. For the toys were powered by nuclear energy. See, on his planet, and with all advanced species, they receive extensive psychological conditioning from birth, so that they can learn how to safely use nuclear-powered hand-held devices. He is horrified to learn that this is not true of the Earth, and he may have unwittingly caused nuclear holocaust on the Earth, for it's children don't know how to safely use nuclear toys. But he is gratified to learn, as he is being led off to prison, that the alien police replaced all of his sold toys with harmless cheap replicas, that will work for a short time, and then fall apart.
I thought of this story as I went in to the bakery to buy some amazing pastries filled with meat. I'm ashamed to say I haven't come across these before, but they are wonderful. They need to be heated though, and the cashier offered to heat them for me. I declined, as I have my own microwave. So he wrapped them in tinfoil- but then made it abundantly clear to me that I must be very, very careful not to put the metal foil into the microwave. I assented, but he didn't feel I was getting the message, and reiterated it to me. See, in America, from an early age, we grow up being taught to never put anything metal in the microwave. We know this; it's 2nd nature. Here in Morocco, microwaves are new enough, and enough of the population doesn't even have one, that they still need to learn the basics. Metal in a microwave is a new concept, and it's not part of early psychological conditioning.