Sure, but I think there should be strict rules along with it. I also think we should be way more strict with alcohol. Really, anything that can alter perception should not be taken lightly. If you're somewhere that you don't plan on leaving for a long while (like your house) then go wild. Can't do anyone but yourself any harm by sitting on your couch getting high/drunk, so whatever. But if you're going to go out somewhere, drive, go to work etc., there needs to be some serious enforcement.

Cigarettes are extremely unhealthy, but they don't alter your vision or render you incapable of walking straight.