I intend to sell a product that has arsenic in its formulation. If I buy or control information outlets that may report on death and injury, if I purchase medical reports on my product, if I manage news outlets regarding arsenic deaths, all legal and proper, then I can continue to sell my product.
This is the flaw in libertarianism. The control of information.
Libertarianism depends upon truth, truth that is somehow guaranteed. The only guarantee of such truth is impartial government. We may not have perfect government bodies but they are far more reliable than anything else.