I believe it was season 5, episode 1, "Deliver It". They focus on UPS but things would be similar for other carriers. The UPS part starts about 9 minutes in. If you have Amazon Prime, they have it for free streaming.
BTW, UPS would be particularly good for intercepts, because UPS operates an electronics repair facility that does factory authorized repairs. When you think you are sending your broken laptop by UPS to, say, Toshiba, it can get automatically diverted to the UPS repair facility a couple miles from the hub, where Toshiba-trained technicians do the repair.
This means that a laptop shipment being diversion for the NSA would not even have to be done with some secret diverter on the line somewhere. They could just make it look like an ordinary repair job. The repair facility is large. Who would know if one or two of the repair technicians are really NSA agents?
BTW, UPS would be particularly good for intercepts, because UPS operates an electronics repair facility that does factory authorized repairs. When you think you are sending your broken laptop by UPS to, say, Toshiba, it can get automatically diverted to the UPS repair facility a couple miles from the hub, where Toshiba-trained technicians do the repair.
This means that a laptop shipment being diversion for the NSA would not even have to be done with some secret diverter on the line somewhere. They could just make it look like an ordinary repair job. The repair facility is large. Who would know if one or two of the repair technicians are really NSA agents?