Back when I was young the feds were involved in crop dusting south of the border marijuana crops using a product called Paraquat which supposedly would (1) destroy the burgeoning crops and (2) cause respiratory ailments to unwittingly stoners.Funny how people aren't generally aware of the fact that "the government" was involved in poisoning alcohol during prohibition that ultimately led to many people suffering (I don't recall if it was blindness and/death or primarily one or the other, I'd have to grab a link to refresh my memory.)
And just like alcohol, once UncleSugar figures out how legally get involved in the distribution racket, the once evil commodity becomes, majikulee legal.