It is true that making a law is how you deal with the conflict between self interest and public interest. However, if you make something illegal that people ha

It is true that making a law is how you deal with the conflict between self interest and public interest. However, if you make something illegal that people have a strong motivation to do, they may just keep doing it, only not as publicly. And in that case, the people who demand ransom will not be particularly discouraged. Their business may improve, because victims will have an incentive to keep the whole thing secret. Think about how people worry that enforcing immigration laws will lead to violent crime being ignored.