Can someone point me to a picture, or screenshot, of this ?
Honestly I care a lot less about ME on servers because at the end of the day, if I see a server misbehaving (sending packets on the wire where it shouldn't) that's going to be a big red flag. Not to mention, egress traffic is indeed filtered. Could they compromise how my applications run? probably. Is there a need to do that? Maybe. Would I see it? certainly.
the concern of ME is for my laptop which many wifi access points have "direct" line access to, it stores all the secrets of my server environment, and even if encrypted a persistent backdoor in ring -1 of my CPU is going to compromise those thousands of servers and in exactly the way I can't defend against.
It's hard to keep up with the cleverness of attackers.
Also, I would guess that it only works if you're using the integrated Intel GPU.
Non-xkcd reference: http://www.bash.org/?291262