Before hitting the hay, I'd like to throw out an alternative perspective. There seem to be a lot of sensational ideas about hijacking and conspiracy, a stolen plane and even cloaking devices. Sure, we don't know what happened, but the scenarios listed are each of increasing improbability.
Take a look at this:
And also this:
These are the flight paths of UA232 and JAL123, respectively. The United flight was a DC-10 in which the fan disk of the tail mounted engine disintegrated, severing all 3 redundant hydraulic systems and damaging the tail. The Japan Air was a B747 which experienced an explosive decompression when the aft pressure bulkhead ruptured, causing all 4 redundant hydraulic systems to fail.
In both of these instances, communication was *not* severed. However, it is not improbable that some catastrophic event occurred aboard MAS370 which crippled the aircraft and also damaged it's ability to broadcast information.
We are now hearing that reports that the EHM snapshots indicating a flight time of 4 hours after ATC lost contact are not true. However, it is possible that the aircraft continued to fly, crippled, in an erratic flight path after this supposed incident. If the flight path resembled what happened on UA232 or JAL123, it could explain why MAS370 has been hard to locate.
Of course, speculation. Hopefully, we will hear some definitive news soon.
[Edited 2014-03-13 03:17:46]
"We fly, but we have not 'conquered' the air. When we presume mastery, we are often startled by our ignorance." - DHW