Genuine answer! You've made me reconsider quite a lot, actually. Intuitively I'd say yes, it should be legal to do that. But then, I would consider that a violation of property, because really, a child is unlikely to understand the consequences of a herion addiction. But then I suppose nobody addicted to herion really understands the consequences of addiction, or they wouldn't buy herion.

Which almost makes me reconsider my entire political standpoint. So thanks! I can't answer your question, but I assure you, you have me thinking.