A Kyoto-based outfit by the name of Fujikata is preparing to launch 10,000 smart cigarette vending machines, each equipped with a face analysis system designed to determine whether you're over 20 years of age (the legal minimum in Japan). If you're deemed too young, you'll have to swipe your driver's license to get your smokes, at which point the machine will presumably 1) dispense the goods and 2) congratulate you on being so well-preserved. One test found the system to be 90 percent accurate.
Why not just have people swipe their licenses to begin with? Trying to guess their age just introduces the possibility of dispensing to teenagers who look wise beyond their years. Further, if you insisted on seeing a driver's license, you could track how much each of your citizens smoked, which could be important public health data both in the aggregate and for individual intervention.
In fact, you could collect a lot of public health data. I mean, you have people standing in front of a kiosk who really, really need what it has to offer—they'll do anything to get it. Why not take advantage? Provide a cuff that will take their blood pressure and pulse; make them stand on a scale; insist that they blow into a tube that picks up lung capacity (and alcohol level). Inconvenient? Demeaning? Sure! But what are they going to do about it? Quit? I don't think so.
If this worked, the obvious next step would be to equip all vending machines (vending machines are very popular in Japan—you can get almost anything from them) with medical diagnostic equipment so you could collect data on non-smokers as well. In the interests of time, it might make sense to spread the tests out across different types of machine. Eye tests would be done at sushi kiosks, for example, while your reflexes would be assessed at machines that sell beer. (Kiosks that did more invasive tests would be equipped with a privacy curtain, of course.)
The Diagnostic Vending Machine could be a powerful public health tool and you'd probably get accustomed to it—with practice, I'm sure that having your tonsils examined ("Aaaaah") each time you go through a subway turnstile would come to seem perfectly natural.