LE use aerial drones for surveillance all the time. Remote controlled mini helicopters that can carry high quality video cameras are actually relatively inexpensive, you can buy really nice ones for only a few thousand dollars and most major police forces have several. If the buyer tells the transporter the drop off location, the transporter will be arrested by law enforcement posing as customer. That breaks anonymity for the transporter and is impossible to do securely. The only way it would have any chance of working is if the drop is made before the customer knows the exact location of the drop. I think that there is future for dead drop transportation as well, but I think it will be for local regions and not using networks of anonymous transporters. I suppose it is possible that it could use anonymous transporters as well, but I think at least it will start with vendors in major cities doing dead drops around their own city for more localized customer bases. For long distance transportation of bulk I still think that mail is likely a better choice, same for small amounts as well although for a totally different reason.