Why the NSA builds its own hardware

quartertime writes: Remember Reflections on Trusting Trust, the classic paper describing how to hide a nearly undetectable backdoor inside the C compiler? Here's an interesting piece about how to hide a nearly undetectable backdoor inside hardware. The post describes how to install a backdoor in the expansion ROM of a PCI card, which during the boot process patches the BIOS to patch grub to patch the kernel to give the controller remote root access. Because the backdoor is actually housed in the hardware, even if the victim reinstalls the operating from CD, they won't clear out the backdoor. I wonder whether China, with its dominant position in the computer hardware assembly business, has already used this technique for espionage? This perhaps explains why the NSA has its own chip fabrication plant.