Of course, in places that DONT want it, restaurants, apartment buildings, condo associations....people will STILL do it. People smoke leaning on no-smoking signs all the time.
This is why these things never work. It would be so beautiful, if it was as simple as "I own this establishment, people can do whatever within my set of rules, as long as it doesn't affect people outside". But people never, ever follow those rules (in either direction), and its very hard to do things that stay within your place (MJ smoke reaches fucking far and leaks through everything).
Thus why its so damn much more complicated. People for it will often do it ANYWHERE, accepted or not, private or public... people against it will be affected no matter where they go. Everyone's losing no matter what.
ie: I live in a condo community (a couple of buildings) on a private street (as in, a fairly long stretch of road that we have to pay to maintain, the city doesn't touch it). Hundreds of people a day go through it even though its a private area, no amount of signs or barriers stop anyone, the city/cops won't do shit about it. And because I'm in an extremely liberal area, a huge percentage of the trespasser are smoking weed as they do. And since the smell has such an insane range, the whole area constantly smell like pot.
NOT FUN.