Clearly they cannot. They had already banned selling alcohol to kids.
95% of the time you will get exactly what you want, otherwise it would be some form of "desolee". This is obvious, everybody knows and sees it, en masse (as in you are choosing from tens of such people in given area).
you ban drugs because of the social consequences of the phenomenon - the damages are evaluated as high.
For other indulgences, social damages may vary.