I'm not saying that it is particularly harmful, I understand that. I am not saying that people who smoke on streets need to stop doing it necessarily, either. I'm just saying that it is unethical for anything to harm anyone without their consent, including secondhand smoke. Obviously a whiff of smoke is hardly going to do anything in the long run, but it is still a topic which needs to be addressed. Just as smokers feel they should have the right to pursue their habit, non-smokers feel that they should also have the right to coexist with smokers without suffering the same body-deteriorating problems caused by first and secondhand smoke.