The "black market" label only exists because governments assert a monopoly over what’s "legal," usually to extract taxes or enforce control. But anarcho-capitalism rejects that premise entirely. Private property and mutual agreement are the only rules that matter.
The brainwashing comes when people internalize the idea that freedom needs permission slips from above. It doesn’t. Trade is trade, and the only crime is when someone uses force or fraud. Everything else is just the state crying over lost revenue.