From what I understand pretty much all Intel CPUs produced since Sandy-Bridge have "secret" 3G capabilities in their IME (Intel Management Engine). This IME has full access to the memory bus and pretty much your whole computer and there is no way to see or block it from your OS.
That sounds incredibly scary to me, as I have literally no way of knowing if my data is being leaked or if malicious code is injected into my system. I mean I can't even be sure to be safe by unplugging my Ethernet cable.
Is it possible that Intel got an NSL and has been forced to implement a backdoor for the NSA? How likely does it seem that Intel is abusing this? Can we disable the 3G connection?