Okay, in that regard the assumption that "the government or its postal system selectively withholds the goods payed for through cryptographic protocols" seems questionable. Is this a real problem that we're seeing in some markets? As far as I'm aware it seems that in general delivery services are decoupled from the payment for goods; the delivery system, no matter if it's government postal system or private parcel delivery, does not know and can not know how (and if) the goods were paid for. They may require some declaration from the sender about the value for insurance and customs purposes, but that's different than the payment data.