Intel & ME, and why we should get rid of ME
Architecturally, the ME varies from model to model, and over the past decade it has been growing in complexity. In general, it consists of of one or more processor cores, memory, system clock, internal bus, and reserved protected memory used as part of its own cryptography engine. It has its own operating system and suite of programs, and it has access to the main system's memory, as well as access to the network through the Intel Gigabit Ethernet Controller. If you had control over the ME, then it would be a powerful subsystem that could be used for security and administration of your device.
The ME firmware runs various proprietary programs created by Intel for the platform, including its infamous Active Management Technology (AMT), Intel's Boot Guard, and an audio and video Digital Restrictions Management system specifically for ultra-high definition media called "Intel Insider." While some of this technology is marketed to provide you with convenience and protection, what it requires from you, the user, is to give up control over your computer. This control benefits Intel, their business partners, and large media companies. Intel is effectively leasing-out to the third-parties the rights to control how, if, and when you can access certain data and software on your machine.
Leah Rowe of GNU Libreboot states that the "Intel Management Engine with its proprietary firmware has complete access to and control over the PC: it can power on or shut down the PC, read all open files, examine all running applications, track all keys pressed and mouse movements, and even capture or display images on the screen. And it has a network interface that is demonstrably insecure, which can allow an attacker on the network to inject rootkits that completely compromise the PC and can report to the attacker all activities performed on the PC. It is a threat to freedom, security, and privacy that can't be ignored."
At this time, developing free replacement firmware for the ME is basically impossible. The only entity capable of replacing the ME firmware is Intel and its OEM partners. And, since the ME is a control hub for your machine, you can no longer simply disable the ME like you could on earlier models, such as the Libreboot X200 laptop.
This means that if in the future we want more hardware that can achieve Respects Your Freedom certification, we will need to make it a "High-Priority" to support the work of those who are getting GNU Libreboot and 100% free system distributions running on other architectures, such as ARM, MIPS, and POWER8.