Just read
this on the incremental "slippery slope" (why do I keep typing that as slipper slope?) of anti-smoking laws and regulations.
Regardless of whether you agree or not with where things currently stand (generally I don't and the last cigarette I smoked was in 1981) try to imagine being back in the early '80s. There's discussion about new laws to ban smoking on airplanes.
How crazy would the person saying "if you pass this law it is just the first step towards them telling you that you can't smoke in your own home, or that you can't smoke in your city park even if there isn't another person with a football field of you?"
But back in 1982 how would you have differentiated this one from the guy saying it'll inevitably lead to the same logic being used to outlaw fatty foods (mostly hasn't happened yet but the logic is starting to move that way in obvious ways) or from the guy saying that it will eventually lead to stoning in the public square of any offenders (still doesn't look likely).