It's a private company. They're free to not hire you for any reason whatsoever. From not liking the curve of your face, to the way your mustache reminds them of that gay biker porn movie they saw back in the 70s, to the fact that your membership of certain internet technical forums indicates your lack of the social skills necessary in the corporate environment, nerd.
As a smoker, I'd be concerned, but with the age of social media and ubiquitous computing, it's pretty much a given this leads directly to actuarial analysis of your lifestyle for costs to the company pre-hire. Casual drinking, rock climbing, walking along busy highways, driving over the speed limit, driving aggressively, going to punk rock concerts. Everyone prepare to be calculated.