The threat is not from unknown robots sneaking in to uproot crops (after all why not do something fast and cheap like spreading salt?). The threat is that the farmer's own weeding robots will be hacked to uproot crops, probably by ze Russians. Firmware updates should be secured.
Actually I like that, it's closer to the essential truth.
I think George Carlin nailed it with his routine about flamethrowers.
> The very existence of flamethrowers proves that sometime, somewhere, someone said to themselves, 'You know, I want to set those people over there on fire, but I’m just not close enough to get the job done.
