A good friend of mine often tells me, "Grice, you know what the problem is with this country?  Anytime anyone doesn't like anything, their immediate response is to say there ought to be a law against it."  That wouldn't be my catch-all to describe the problems of the post-industrial north, but there's some truth in it.  The drug laws are only the most extreme example of the negative consequences this mindset can bring about.  
But as much as I'd like to move on to a future based entirely around consensus and community without a need for a state and apparatus to enforce its laws, I'm not prepared to give up the good laws in the meantime.  Some of us may even owe our lives to such things as health, safety and environmental laws, which even when not well followed or enforced have often served to eliminate some of the worst abuses.  So the question becomes where to draw the line.  And it isn't an easy one.  
One thing that helps me here is that a smoke filled bar is obvious and more or less avoidable.  Mercury poisoning from industrial emissions is neither.  An unsafe machine in a factory may or may not be obvious, but making it safer shouldn't have to fundamentally affect what that factory produces.  But banning smoking does fundamentally affect the quality of the bar experience for many patrons.  Anti-smokers have every right to complain, but I don't think they have the right to impose their will on all bar owners and patrons.  Loud music can damage a person's hearing, but should those concerned be able to force every band and DJ to keep the music turned down so they too can come out to enjoy it?