Years ago, I purchased (off The `Bay) a Paul Simon reel-to-reel tape. The seller packaged it in a white plastic bag, stuck a label on it, and mailed it. I received the empty bag, which had been surgically sliced open along one end.
I took the bag, and an LP version of the album, down to the local Post Office. Showed them the empty bag, then the album, and told them "THIS is what is supposed to be in the bag, but a slightly smaller box."
One of the workers called out "Ooohhh....I saw that on a shelf in the back !"
So, there was a good ending, I got my tape back, but I`d still like to know who was the bonehead that opened my package, and then forwarded the empty envelope....