How is that analogous to hacking a device so you can tether to it and use its data plan to avoid costs yourself?
"Your Honor, that sign on the entrance to the parking lot discussing parking restrictions and enforcement thereof somehow implied that they're giving me this device and authorization to use it how I see fit".
I suppose if someone leaves their wallet on the hood of your car while they're tying their shoelace, they've also authorized you to use their credit cards, right?