I'm in Malaysia. Feeling very horrible about all of this, and following very closely.
Reports that 4 (including the stolen Austrian and Italian) passport holders with dubious identification, possibly also a Chinese passport number of a man in China (not on flight).
Oil slicks and reports of debris in various places, nothing identifying.
Possible change of route.
5 passengers apparently not allowed to board, luggage removed before takeoff.
Also, reports of phones of passengers being contactable, but not answered. Would this be the case under the ocean? 
We don't know what to think. Everyone is very shaken by this. Could it be a terrorist attack? By whom? What for?
Mechanical fault? Why no distress signal? Especially if they headed back.
It makes no sense 