You're right and I'm wrong! I'm currently editing my summary to clarify. Still, I believe having full control on the firmware of the phone modem is at least a

You're right and I'm wrong! I'm currently editing my summary to clarify. Still, I believe having full control on the firmware of the phone modem is at least as important as having root on the phone - otherwise, the firmware can say "location off? no problem!" while continuing to get GPS position locks + transmit the position inside UDP packets that won't be visible to the CPU running the android kernel and communicating to the firmware. EDIT: actually, you are partly wrong when you say "This just replaces that part which you can already edit on your own Android phone": many android phones use a modem module to have certification in different markets. So you can't replace the modem firmware on most android phones I'm familiar with. Don't be confused by the modem using adb and fastboot like the android phones: it has its own software stack, and runs its own OS a bit like Intel ME or AMD PSP on PCs.