The banking system is rather complicated. I think it would be possible to overdraw in some situations. See also this article where hackers stole $45 million fr

The banking system is rather complicated. I think it would be possible to overdraw in some situations. See also this article where hackers stole $45 million from ATMs: http://www.nytimes.com/2013/05/10/nyregion/eight-charged-in-45-million-global-cyber-bank-thefts.html http://www.nytimes.com/2013/05/10/nyregion/eight-charged-in-...