The day Optus went dark

We all expect network failures sometimes, patchy internet and drop outs in phone calls, but Optus has taken it to a whole new level.  Not only were 10 million customers left without service for half a day, but for hours the telecommunications giant said it had absolutely no idea what was wrong.  Today, technology expert from the University of Melbourne Suelette Dreyfus on how an outage like this can leave us all vulnerable.  Featured:  Dr Suelette Dreyfus, University of Melbourne School of Computing and Information Systems