I began trying to phrase my comment above in a fashion as "values free" as possible simply to illustrate different "enforcement challenges" in different crimes. It seems the comments keep coming to back my comment being interpreted in value-based fashion.

Not that I wouldn't want to engage in a discussion of the merits of drug legalization but here I'd want keep the thread that "victimless" can simply be conceived of as a "how" question concerning a particular kind of act without recourse to asking the question of "whether" the act should happen.

In the crimes usually described as victimless, the main thing is that all the individuals "actively involved" are seeking to make the act happened. To say this is not to claim that those who might be effected once the act happened aren't harmed, scared, victimized, etc. We would thus distinguish "active victims" (those mugged, murder, robbed, etc) and passive victims (relatives, friends, society...). So we could perhaps distinguish "active-victim-less" crimes and say all crimes have passive victims - for those who want this set of value judgments.

Can I get more clinical?