I'm not sure why the fundamental problem here is that people are stealing, rather than that a known billionaire is willing to operate a business that is known to be an attractive way to profit from theft. You almost certainly can't eliminate theft without predictable laws; no one ever has, and to the extent that it's been reduced, the existence of a reliable legal process has been part of it.
And Amazon can't exactly plead "plausible deniability" in an absolute sense here, because they ought to be aware that they're acting as a fence, and they ought to be aware that their processes are insufficient for reducing the degree of theft that's going on. If they've deliberately chosen to be ignorant of those facts, it would actually raise their level of culpability.
Finally, your analogy of legal solutions to technical solutions fails. In a democracy, legal solutions exist to meet the burden of social expectations. They do not stand outside of society. Unlike democratic laws, technical solutions are usually imposed on a community by people with disproportionate power - laws are created on a one person - one vote basis, but technical solutions are usually created on a one dollar - one vote basis. Therefore, technical solutions are usually not responsive to the needs of a society, and are far more likely to represent someone's One Fantastic Idea to Solve All Problems, rather than a compromise of interests resulting in social norms that can be imposed on defectors.
This is exactly an occasion when existing laws should be used, rather than plea for the devaluation of trust and law by ignoring laws simply because they might be applied against a powerful person.
And Amazon can't exactly plead "plausible deniability" in an absolute sense here, because they ought to be aware that they're acting as a fence, and they ought to be aware that their processes are insufficient for reducing the degree of theft that's going on. If they've deliberately chosen to be ignorant of those facts, it would actually raise their level of culpability.
Finally, your analogy of legal solutions to technical solutions fails. In a democracy, legal solutions exist to meet the burden of social expectations. They do not stand outside of society. Unlike democratic laws, technical solutions are usually imposed on a community by people with disproportionate power - laws are created on a one person - one vote basis, but technical solutions are usually created on a one dollar - one vote basis. Therefore, technical solutions are usually not responsive to the needs of a society, and are far more likely to represent someone's One Fantastic Idea to Solve All Problems, rather than a compromise of interests resulting in social norms that can be imposed on defectors.
This is exactly an occasion when existing laws should be used, rather than plea for the devaluation of trust and law by ignoring laws simply because they might be applied against a powerful person.