More seriously than previous post,

This phone is interesting for replacing the n900.
I feel I'll risk to get blamed to ask this: I read lots of posts here but often too technical for me. So the question:

Is it really sure that this kind of devices (Fx or Purism) offer real privacy?

I know they have open source software and drivers but is it sure that nothing can happen (collect data, position, mic, cam) on a lower layer/level into the hardware?

Sorry if my question is a bit naive.

Thanks