PinePhones on assembly line

[theD0ctor]

 A small group of transistors will never be able to phone home. Functional blocks can.

?? sure it can... Also functional blocks = diagrams, just a visual representation of code. A group of transistors can enable the engagement of some other analogy circuit that is then itself coded with a backdoor (ex. trojan). Point is, the backdoored analog circuitry would not be known or detectable due to downstream events of hardware triggering it:

• In June 2016 it was reported that University of Michigan Department of Electrical Engineering and Computer Science had built a hardware backdoor that leveraged "analog circuits to create a hardware attack" so that after the capacitors store up enough electricity to be fully charged, it would be switched on, to give an attacker complete access to whatever system or device − such as a PC − that contains the backdoored chip. In the study that won the "best paper" award at the IEEE Symposium on Privacy and Security they also note that microscopic hardware backdoor wouldn't be caught by practically any modern method of hardware security analysis, and could be planted by a single employee of a chip factory.[16][17]
  

Argument is, if you were to be so worried about HW backdoors, there is almost nothing that can be done about it if it can be enabled at such a low level such as transistors, which it can... And for a sophisticated attack such as that, there are numerous other devices everyone uses other than pinephones to be better risk vs benefit scenario