I think Paypal are so nervous about fraudulent transactions that this is one situation where the seller is seen by them as guilty until proven innocent. If the person who bought the goods says he did not, his money is refunded and Paypal will seek to get the money from you. Also, with warnings like this it allows people to appreciate how the scam works so they can indeed get a receipt for the goods etc from the buyer. Let's face it, if you sold something on Ebay, had payment in your bank account already via Paypal and a bloke at the door to collect as arranged, would you actually bother with getting a receipt? Before reading about these scams, I doubt I would.