Credit card chargeback is one example:
https://www.paypal-ma...e/ChargebackGuide.htm
And buyer collects and claims Item Not Received.
One such criteria is when accepting Paypal, you must be able to prove to Paypal that the buyer has received the item. This is why, regardless of value, all my items are sent via a signed for service. If you cannot prove an item has been received, the buyer can open an “item not received” claim against you. If this happens on an item that has been collected, you could not prove this and Paypal would refund the payment in full leaving you without the item and without the money (& maybe a negative balance in your Paypal account & threats of debt-collectors).
http://reviews.ebay.c...gidZ10000000004503860
I am shocked that some eBay sellers are unaware of this scam. The eBay community boards have lots of disgruntled sellers complaining about this and PayPal make it very clear that to qualify for Seller Protection you MUST post the item using approved services that provide an online tracking number.