Why doesn't it make sense? Drug dealers spend megabucks moving drugs. A largely anonymous network of couriers with no idea what they're carrying would be ideal. They wouldn't move a ton at once, they would spread it out over many smaller shipments. Since the oversight is zero and the cost is so low it would be worth whatever extra hassle it might add. Imagine an undercover fedex that didn't ask questions. I'm sure you'd be the go-to network for a while until you got shut down.