Well that's why FUD spreaders do their work.
If we were to go in further and analyze this in details, we would find much wrong with the allegations. Same thing with that USB bug. Taking into consideration the number of USB devices, people that could implement the virus and the amount of devices that have been actually 'modified' the chances of you getting infected are almost impossible. Yet that scared people of this community.
The Intel AMT feature can't be on and set up by default. That would be a major flaw, and would have been discussed long ago.