There are some people who think that since the research on e-cigs indicates that they are likely a safer alternative to cigarette smoke, that that means e-cigs are 100% safe. There are others (who tend to be assholes anyway) that think because the law only prohibits smoking that that means e-cigs can be used in any public space with impunity. I know that the e-cig communities online, generally do not advocate this kind of behavior. Honestly, the worst way to go about winning people over and selling them on the idea that e-cigs are a much less harmful alternative to smoking, is to blow vapor in their collective faces. In any event, blowing smoke (or in this case, vapor) in someone's face is pretty much always a challenge of some kind, unless of course, it is by accident.