It is extremely unfortunate, but this has been an issue for some time. Almost anything can be hacked into these days... need a good example? Pick up any Macbook Pro notebook, and it's possible for someone to very easily reprogram the battery to cease working, or even worse.
Modern "smart" batteries that can self-regulate are great and come with many advantages, but just like anything else that uses firmware, it can be reprogrammed. Apple apparently didn't give it any thought and used the default name/pass on the battery controller.
http://arstechnica.com/apple/news/20...ttery-hack.ars