A number of Australian Apple device owners have discovered that their devices have been hacked, and are being held hostage for ransom, reports the Sydney Morning Herald. iPad, iPhone, and Mac owners have reported seeing messages stating their device was hacked, and would be unlocked if they sent money to a PayPal account. In some known cases, the message “Device hacked by Oleg Pliss” has prompted users to send $50 or $100 to a PayPal account.…