Completely locking down a physical device and making it unhackable is downright impossible. If the attacker has physical access to the device and the ability to

Completely locking down a physical device and making it unhackable is downright impossible. If the attacker has physical access to the device and the ability to regulate network access, then it's only a matter of time before the device gets hacked. Right now they are using USB to gain access to the device. There is nothing stopping an attacker from actually prying open the device and fitting alternative components that can bypass security. Consoles are cited as an example of an unhackable device, which is not true. Consoles were designed to be unhackable by cheap mass-market methods but a determined hacker can still do it, just that he will have to spend more to do it than the cost of a new console. The hacker in this scenario is FBI with a lot of money and resources with the physical device in their custody. I doubt if FBI is going to lose the ability to hack devices anytime soon.