As many of you are familiar with by now, selling Bitcoins on PayPal is not smart. Once you send the Bitcoins, all the buyer has to do is dispute the transaction, and you will lose out on your Bitcoins AND the money they paid you.
This is where the problem lies. What we're talking about is trust here and most people aren't establishing that before sending their BTC.
Here's one way to stop 99.99% of PayPal scammers:
Ask for a $1 payment to receive a confirmed shipping address and phone number. Afterwards ask for PayPal Mass Pay funded by a Money Pak. Send a consent email asking the buyer to acknowledge payment was authorized. Ask for screen shots of the Money Pak. Check Email headers to make sure consent form is sent from the same email. Next check if phone number matches address. Get IP address and check if it matches with address. Ask the buyer to open up a dispute and close it. Then do a Google background check to make sure nothing else out of the ordinary.
And if you have no idea what I just said then you probably shouldn't be accepting PayPal at all.
Mailing something on eBay doesn't work. It works against amateurs, but not against real scammers who know the system better than you.
They can refuse your shipment after you sent the BTC to their client. And if you wait until after the shipment arrives, then no one's going to buy from you because they want virtual items delivered quickly. After shipment a credit card chargebacks would still stop you cold. The issuing bank does not care or know what's going on about BTC and there's no real proof you can submit that the issuing bank will buy.