[homonculus1]

The scary part is that drugs were only volunteered as an offhand example. Authoritarians (in this case openly) apply the same logic to literally any activity, such that even the most vague and indirect tertiary externalities can be twisted into an excuse to police other people. Even the most responsible engagement in [drug use]/[sex]/[motorcycle riding]/[controversial art]/[self-defense]/[political protest] is subject to their judgment and approval because your example might influence someone else!

But even though this loose standard can be stretched to justify literally any prohibition, in practice the only activities that get targeted in the name of community enhancement are the ones that make the group in power feel threatened or uncomfortable.