Never had one lost but I had them destroy a package (I guess from the sorting machines) but these fukkers taped up the cardboard container (a poster was inside) and delivered it with a "We're Sorry" note attached. Naturally I was heated but unless the sender puts insurance on it, theres nothing the USPS can do about it. So I took some pics of the damaged package and sent it to the place where I got the poster and they sent me a new one.