If the smoke was so thick and so massive that it flowed in and caused a fog, I could almost...
almost understand this.
However, from the 7 years I spent in San Diego, California has been heading this way for a long long time, and I'm highly doubting this was the first instance of it. In one of the little provinces for a short time you could only smoke in your car with the windows up *yuck* OR your own home, as long as a child was not present, and it had to be inside your home. I can understand the child, but the fact that smokers are and always will be treated like second class citizens in California is idiotic, but the cold hard truth.
On the other side of the ball, if you're trying to have a nice open air day, maybe sitting on a patio of a restaurant, and a gaggle of ......... smokers come by and light up and keep wafting all that smoke right in their face and way.. now there's a good reason to be annoyed, and I'd agree they would be in their rights to take legal action for intent to cause bodily harm. As that type of behaviour is irresponsible with an item that is known to cause many, many health issues. It's not the responsibility of the non-smoker to leave, just because a bunch of irresponsible smokers show up and screw up their quality of air thinking they're more important because they smoke and that they're outside already.
If they attempt to remove themselves from the populated area and go off to a quiet corner where noone else is getting harassed, and maybe, just maybe a little smell comes wafting
through.. then you have the option of moving, or dealing with it. Legal action shouldn't even be allowed or considered because if smells could kill you I'd have died to the nasty stench of our restaurant's grease trap long ago.. though strangely breathing enough of that actually will kill you, and they're a ..... to clean. >_<