I'm invoking "walled garden", speaking of closed, controlled hardware environments in general, whether that be Apple or phone carriers or laptop manufacturers or the like. Once the controllers of that environment gain power, the human tendency to abuse and extend that power is only a matter of time.

The only way to ensure that you can trust the hardware and software you use is if it is 100% transparent. And while that is not always possible, the ability to control what runs on your own hardware goes a long way towards mitigating the risk of a betrayed trust.