Well, do you mean “if” alcohol or cigarettes were illegal? It’s hard to say, since that’s sort of a sci-fi scenario, other than during Prohibition. Or if my father ran a still in the basement? Maybe I would call Elliot Ness. I don’t know. Or calling the cops about cigarettes? It’s too whimsical and far-fetched to use as an analogy. Considering their longstanding legality and cultural standing, I think the onus would more likely just be on me to move away.
But dope? Hell, yes. If some sibling or cousin came to my house and pulled out some dope, I’d personally beat them to a bloody pulp and then call the cops. I’d never even want to see them again.