Cities running on sensors
I would talk about how to hack a smart city. If we ask as to what is a smart city, it is network of intelligence sensors. Sensing various parameters, you can get some live examples as demo that is available on internet that showcases methods on how to hack.
All the doomsday scenario shown in movies can actually happen. For example, maybe a single light moves with instructions or on a SCADA device. If it has an interface, it can be accessed and if it is accessed, then it can be hacked, too. Even the most expensive equipment like the CCTVs can be exploited easily. About 99 per cent of default devices are able to change. Once you have a smart city, you will have a system which might not be in your control.
It will be like something is manning your system and tinkering your system. All things you use have an embedded operation system on all hardcore devices. Tomorrow, transportation, health, water disposal is going to be controlled by smart system, but they need to be smart, and a way of communication should be devised for accountability.