I do wonder though that had Apple not predicted this exact scenario ahead of time (likely), how would they control this? It's unlikely they can rely on hardwar

I do wonder though that had Apple not predicted this exact scenario ahead of time (likely), how would they control this? It's unlikely they can rely on hardware protections to provide this device locking, so is it the case that they would build the unique identifier into the image. Optimistically some obfuscation could help but are the FBI/CIA/NSA really more than a few hops away from opening the binary image in a hex editor and changing it by hand? If Apple firmware images for the iPhone are signed per-device then fine, but is that the case? I don't know this but it seems unlikely to me that a custom device-signed build of iOS happens for every iDevice, and if that's not the case, I can't see how Apple can reliably restrict this with confidence.