This scenario is not far-fetched at all; the Snowden documents indicate that the NSA is already doing exactly this: - http://www.engadget.com/2014/05/16/nsa-bu

This scenario is not far-fetched at all; the Snowden documents indicate that the NSA is already doing exactly this: - http://www.engadget.com/2014/05/16/nsa-bugged-cisco-routers/ http://www.engadget.com/2014/05/16/nsa-bugged-cisco-routers/ - http://www.theguardian.com/books/2014/may/12/glenn-greenwald-nsa-tampers-us-internet-routers-snowden http://www.theguardian.com/books/2014/may/12/glenn-greenwald... - http://www.theverge.com/2013/12/29/5253226/nsa-cia-fbi-laptop-usb-plant-spy http://www.theverge.com/2013/12/29/5253226/nsa-cia-fbi-lapto... - etc. At the very least, shipments should be made in a strongly tamper-evident container.