I live alone at the moment while my wife is overseas. I keep Skype on 24/7 in case she needs to get in touch. I went to bed with over AU$15 credit and woke up with an AU$0.05 balance and with two $16 credit top-ups made via PayPal.
Checking my call history, there were recently 5 unauthorized calls made to Taiwan from my account.
Clearly there is a security problem with Skype that needs to be addressed ASAP.