I had an express post item stolen from my front door a month ago. My bedroom is right next to the front door. I was awake but still in bed . I heard the delivery bloke drop it on the ground and as I knew what was in it, I knew it was the right sound hitting the ground. 

A minute later I heard footsteps again and thought he must have missed something and brought it in. I got straight up,  went straight to the door and nothing. The second footsteps was someone coming in and stealing my package. I suppose a bright yellow satchel stuck out like dogs doodles and was too tempting for the low life. Not a thing I could do about it.

If I was a nasty person I could have told the seller it didn't arrive,  but I would assume the tracking would have said delivered  (he didn't give me the number ).

I have to wonder if some of the items that are saying delivered where the buyer hasn't got it, if they too may have been stolen. Especially if they were express items sitting at the front door. Mine was taken in under 90 seconds so I could  assume in some cases it could be possible. 

My delivery guy did confirm that he had dropped that express satchel off the day before.