So basically, if you send someone $1000, all they need to do is send you a box with nothing in it, but a delivery confirmation sticker on it and you're completely SOL.
Yup, last summer, I bought a pair of those cute tailored shorts from a seller. I received a VERY thin empty envelope (which was barely closed, you can tell someone opened it from the flap then resealed it) and I complained to the seller. She told me "once the item leaves my hands, I am no longer responsible unless insurance is purchased." So I couldn't get a refund or anything because of that. The only thing I could do was file a postal complaint but obviously nothing ever came of that. So I was out my $20 and couldn't do a thing about it.