It's not just the privatised royal mail or the US post. I ordered a 500 euro ww1 medal 2 years ago around Christmas time and the fedex delivery man just left it on the mat outside my front door even though it needed a signature. Obviously it was stolen but I had my money back from the seller instantly who claimed it all from fedex
Had it happen twice in one weeks time...here is an example of one of the packages...The package looked completely intact, no overt malicious cuts or tears from the outside. Opened the package with one cut of the package at the top. Resultant inside packaging had been cut into, both layers. The coin removed from the coin holder and holder replaced. Upon closer inspection, looking from the inside of the outer packaging you can see where the package was cut and taped over externally with Ebay tape. I was fully refunded from both malicious thievings.