Read this from Wired; Its a bit of a worry as we dive further into the connected world the security of any critical system is going to have to be factored at the beginning of development not as an after though, especially devices like cars, medical equipment. Wi-Fi enabled pace makers and insulin pumps have already been hacked now cars and maybe aircraft.
http://www.wired.com/2015/07/hackers-remotely-kill-jeep-highway/