However, it helps to pay one's own debt to society before calling in someone else's.
I personally had to file a fraud dispute with my credit card company after receiving two promises over two months to reverse an unauthorized charge PayPal put on my card at their own (not a third-party vendor's) behest.
I've yet to read a story where PayPal did something unethical, despite the monthly PayPal stories on HN. All of them have involved practices (freezing accounts, almost always with very clear cause, holding funds for 180 days, etc.) that are well within their terms of service AND identical to the policies of every merchant account provider in the US.