Money sent through PayPal and any other money transfer service that accepts credit cards can be easily reversed by the sender, even after several weeks. Therefore, you should only accept PayPal in trades with people you trust very highly.
This is why newbies are not likely to sell their PayPal USD for bitcoins successfully.
Some other services that are not totally safe:
- Bank transfers (ACH, etc.) except wire transfers
- Most gift cards.
- Moneypak
- AlertPay
- Paysafecards
- Dwolla
- Western Union (they reportedly will sue the recipient to recover money in some cases)
This is exactly what I was talking about in my post, that's why I rather take btc for payment than paypal, easy way to scam or to get annoyed by customers that don't know what they are doing, in my personal case I only accept btc as payment, that way I avoid all the headcakes that a transaction might have, so I always advise to make transaction with customers in btc or cryptocurrency, and for buyers make sure your seller is a refer seller or has people that vouch for him/her, that way you can make sure it is a legit seller from trustworthy sources