Are you sure? That would mean that every computer on the internet could be accessed through a hardware backdoor in the CPU. Does AMD have all the codes? Is it an unpatched zero day? I believe you, most devices can be remotely accessed and controlled with the right tools, I'm not convinced that all of the processors are there. Intel's processors have a "High Assurance Platform" mode, the NSA uses it to secure their computers. If every processor has a key, who administers the lists of keys?

End to end data encryption will not secure the contents of an iPhone from access by Apple's undocumented remote administration capabilities. I previously wrote an article on RA as it applies to ghost touch and planned obsolescence. https://www.linkedin.com/pulse...

Amazingly, my iPhone SE became unresponsive to touch input when I attempted to use a PayPal QR Code. I omitted this detail in my account of what I allege to be a deliberate administrative limitation, this is the second time the phone has lost touch input. Apple’s Remote Administration and Disabling of Devices https://medium.com/@benjamined...

Certainly most retail workers, Apple Store employees included, could be earning higher wages. It would be helpful too if they had better access to the administrative controls for Apple's devices. I recently visited The Apple Store for assistance with a disabled iPhone SE, they were unable to remedy the problem, their diagnostic procedure lead to a recommendation for the unnecessary replacement of a hardware component. The Apple Store employees are not even permitted to acknowledge certain problems related to the administrative policies of Apple Inc., this is clearly an indication of their collective lack of status in the organization. Details of the store visit and technical problems are further described in "Apple’s Remote Administration and Disabling of Devices" https://medium.com/@benjamined...

Mr. Hoffman-Andrews's advice is well stated and certainly true, it would be helpful to know that Microsoft, Apple, and most manufacturers of Android devices will share your screen data with public Wi-Fi network administrators. They're probably "safe."