>>21757386Nah, it was literally the US government. After all their underground nuclear warhead tests, after aboveground tests got banned by treaty, they started doing them underground. There was a fear that the radiation would get into aquifers and such and affect the food supply so they sent out guys in helicopters, killed some livestock, took their thyroids for testing back at the lab, and then flew away. They didn't want anyone to know about the tests, it was still the Cold War, and they didn't want to cause a panic about radiation in the food supply. They also probably didn't feel much like compensating the farmers for murdering their livestock.
There may have been copycats and people looking for attention, kids doing pranks, etc. but that's how it all started.