There's a not very fine line between being a vociferous advocate for one's pet project and simply grasping at absolutely any straw that might be used to browbeat people into doing as you tell them. Take, for example, the anti-smoking campaigns. There's no doubt at all that smoking can be harmful to those who smoke: it's also true that the smell of smoke is something that many non-smokers don't particularly like.
The anti-smoking campaigners did rather go overboard with their claims of the effects of second hand smoke though: it simply isn't true that thousands die from the effects each year. There is now, because there seems to still be this recalcitrant 20% or so of the population who just won't do as they're told, a move to ever more blood curdling descriptions of the effects of third hand smoke:
Parents who do not smoke in the presence of their children, including even those who smoke only outdoors, nevertheless put their children at serious risk of "massive damage" to both skin and nerve cells, since a neurotoxin in thirdhand tobacco smoke penetrates the child's skin, according to recent research in Germany.
That is the American version of ASH, not the UK, but then things that happen over there tend to turn up here 6 months later, as we all know. The only problem here is that this "research in Germany" is not in fact research in the form that you or I would use the word. It is in fact:
A press release, without any accompanying study, by researchers at a textile institution which aims to market, and profit from, the sale of protective clothing sold to parents who they are able to scare about the potential toxic effects to children of touching a smoker's clothing.
And, mops to clean up that third hand smoke, that's the other thing they want to sell.
Now of course here we come to matters of opinion. Perhaps this is just overzealousness, something just in the pursuit of a righteous and noble goal. Perhaps it's simply the blindness to reality which is the mark of the zealot. Myself, purely as a statement of opinion of course, would say that it's outright lying by those who really cannot stand the fact that quite a lot of people still insist on charting their own path from the cradle to the grave.
One of those matters where it really is incumbent upon you to make up your own mind: just as it ought to be about whether you wish to smoke or associate in public with those who do of course.