You'll still need police, prisons, etc. But you could reduce their size as less people will require the attention of those state organs. People usually know tha

You'll still need police, prisons, etc. But you could reduce their size as less people will require the attention of those state organs. People usually know that what they are doing is wrong, and would rather avoid doing it. Of course some are reckless, but that's what you still have police for.