yes because let's keep this in mind: the 3g, 4g, UMTS you name it are all versions of the GSM communication system.
It started in France, in the late 80s when a firm wanted a mobile phone network, but it was under Mitterrand, a socialist fuck who always wanted to act like Big Brother, and the DGSE had a lot of influence on the design of the GSM network, infrastructure and terminals. (Groupe Systèmes Mobile) notably the fact a phone is sending rx/tx frames in the network every second, just like a bacon would, and a network could make the phone act like it was in-communication. Open mic. without anyone to actually suspect it. Also works for the data services.
So they decided to make it secure, but just secure enough to make sure the communications CAN be intercepted, and phones hacked. Smartphones aren't any different, all the G's you want are just extra layers on the GSM infrastructure and dependent of it. The GSM part of every smartphone is indeed a subsystem, vestigial and vulnerable, with extra stuff added on it. a RISC processor, more ram, an OS anything you want, even an all in one chip like Qualcomm's and co. and all remains designed to be hacked. I wrote a more detailed article on the subject a while ago but rest assured the means to intercept whatever travels in air through any mobile device exist, and were shared between a lot of governments and states in Europe and the US.
I just don't like the idea of calling that thing an OS on its own, it's more like, the BIOS of a PC, or electronic logic running some primitive but efficient code, but not a secondary OS.
There's even a few things Stallman might not know.
