Thank you Albert, good advice taken.
Further investigation alarmingly reveals:
From Paypal website, agreement form:
"4.3 Risk of Reversals, Chargebacks and Claims. When you receive a payment, you are liable to PayPal for the full amount of the payment sent to you plus any Fees if the payment is later invalidated for any reason. This means that, in addition to any other liability, you will be responsible for the amount of the payment sent by the sender, plus the applicable Fees listed in Section 8 (Fees) of this Agreement if you lose a Claim or a Chargeback or if there is a Reversal of the payment. You agree to allow PayPal to recover any amounts due to PayPal by debiting your Balance. If there are insufficient funds in your Balance to cover your liability, you agree to reimburse PayPal through other means. If a sender of a payment files a Chargeback, the credit card issuer, not PayPal, will determine who wins the Chargeback."
Yikes! Chargebacks are what happens when a credit card user or a bank files a claim because of a charge on a stolen card. Really, the bank will decide if you need to pay them back... and paypal can access your accounts to make it so?