I know UPS isn't the preferred shipping company. But I worked on the inside for about three years, supervised both unloading and loading of trailers and package cars, and the small sort (letters and boxes the size of a coat hanger or smaller) not sure if you guys have any interest but if my knowledge helps anyone I consider it a success.
Three years there and I never had one of my 80 something employees come up to me and say "I think this package has drugs in it." What you need to understand we expect these guys to unload at a rate of 1000 pieces/hour. That's about a box every 3 seconds and that doesn't give much time for them to inspect packages. And it should be noted a lot of these guys don't care as long as the package isn't leaking a hazardous material. Keep in mind the shift starts at around 3 am and if its hot or cold that day forget about it. Our job is to get the packages out asap so our production numbers look better.