postal workers do...
from the new york times: "A woman who had left her Postal Service job because of psychological problems shot and killed five former colleagues and critically wounded another at a sorting plant here Monday night before fatally shooting herself, the authorities said Tuesday".
i can't think of any other product, designed solely for killing, that is allowed to be sold to anyone without a criminal record, and the government does nothing to stop its use. in fact it does everything in it's power to protect the industry, by allowing bans to expire; that sort of thing.
now if that isn't criminal, and insane, i don't know what is!