I've lived in a few apartments that had smokers next door and the smoke would get in and hang out and just stand there. I never personally minded that much but I don't have children or any common medical conditions that would make that more then just a yucky. And in a place like san fran where real estate is at an extra premium people get little apartments and if you get the lucky of being between two smokers you could not buy a pack and still get your nicotine with that awesome fog of cigarette smoke. And if you can't imagine that being a problem just realize you could end up living next to someone that chain smokes Captain Black Grape or whatever blend you can't stand. Or that old guy that somehow smoked cigars that he chomped on for hours giving that yummy soggy cigar smellBack to the original topic at hand, I can see why a municipality might enact an indoor apartment smoking ban. With shared walls and other systems, smoke (particularly cigarette smoke) can easily make its way into other apartments and pollute the air in someone else's home. While I believe we should have a strong right to do what we want in our own homes, I also believe that the right to control whether or not we have clean air should trump that right. Simply put, if the action you are taking is making someone else's life worse through no fault of their own, then it's not necessarily your right to do it.