This is a scary thought...
The brand new Boeing 787 Dreamliner has internet access in the passenger compartment for all to use. The problem is that it is on the SAME NETWORK that the airplane's flight control, navigation and communications systems are on. Nobody has hacked it yet but, it could be a matter of time.
I can just see it now. Some 16 year old script kiddie plants a backdoor trojan on a 787's computer and then decides to fly it like his own big Radio Controlled airplane.
More info here