used paypal more than 10 years. recurrent payment wont happen in diablo 3, it only happen if u set it or u puchase item online that u had agree to make recurrent. therefore in your case it is not diablo fault. it was ur paypal who had been compromised. which i suspected that the thief use it for their diablo purchase. nothing to do with diablo use it unauthorized. that how i believe. or maybe u use some kind of application for your diablo such cheat (which most people fall into trap) who actually act as keylogger to log ur paypal password.

yah. that what I am thinking. there is no way playing diablo alone will enable hacker to get paypal account. unless he using same password for all his accounts.