Summer bhaiya...that's too extreme :P
I personally, am against even BANNING smoking and drug abuse. I do find all of it disgusting and it's extremely repelling to me when I even get the smell of the cigarette smoke.. I just walk away and maintain distance if I see anyone smoking.
But.. I dont think it should be banned. People should be free to use anything as they wish. Who are we to tell someone to stop doing something? The person's got brains, he should know he's smoking at his own risk...why should we be "concerned" about him when he himself isnt?
And, I'm sure all the smokers and drug abusers today have good knowledge about harms caused from smoking and substance abuse :)
And about the harms caused to non-smokers... if a non-smoker is so concerned about his health, he can always move away or put a hanky across his nose or else, better alternative - there should be "zones" where one cannot smoke in public/restuarants etc...which already exists in many countries.