Pardon my silly 'Aliens did it' post (but, however unlikely, that can't be simply dismissed).
It seems obvious now that people/a person in the plane carried out the action.
The transponder providing details of the plane itself and its location was turned off and so it disappears from radar - civilian radar. (Military radar does not rely on transponders - attacking planes and missiles don't use them.)
... On Saturday, Mr Razak said the jet was deliberately diverted off its Kuala Lumpur-Beijing flight path, and may have flown for nearly seven hours after it disappeared from civilian radar. ...
Early this morning ABC radio news said satellite info suggested the plane had flown for at least 6 more hours after it was lost to civilian sight.
I would think that military radar of various countries would have picked up the plane whenever it was in their particular area - and it would seem natural to me that radar images were constantly cross-checked against known traffic (with civilian traffic data being instantly available world wide).
Obviously, I have no idea what areas are blind spots to all military radar, but I think there wouldn't be many or much.
The ABC provides this -
The north-western path must surely move within the radar scope of several nations, and one country could not be the only one to see it.
The south-western path is into (across) the Indian Ocean - not much there with regards to military radar, except for the Diego Garcia US Base. (I would assume their military discovery/detection/defence ring is both large and thoroughly effective.)
In essence, I do think that the plane's disappearance was not the result of an accident - pilot error or structural - but a deliberate act by some persons on the flight.
I don't think it was the action of a terrorist group, particularly not a terrorist group acting alone.
I think there must be involvement at a state/nation level, but cannot point a speculative finger at anyone.
I've no idea of the motive for it, but think perhaps it must be part of something a lot bigger that we will experience in the time to come.
