The voluntary interactions between humans comprise the free market. Some voluntary actions still can have negative outcomes, such as in the case of scams. Depending on the amount of freedom a society values, these outcomes can then be dealt with violently or nonviolently.
A scam is a confidence trick: “an attempt to defraud a person or group by gaining their confidence.”
Fraud is a serious issue. It is theft by deception, but does not necessarily require the same response as physical aggression. If violent people cannot be reasoned with, then violence may be the answer. When fraudulent people cannot be made to stop their fraud, and return the money, then either violence or a strong reputation system may be the solution.
Fear of imprisonment may be a deterrent to crime, but physical incarceration is a blunt tool hitting a unique situation. Having systems in place to track the goodness of an individual in society is the future of civilization, and even workable now.