There's a thread about it downstairs, but there's no reason to not have one here. As I pointed out there, it's not an act of a terrorist organization because no one's claimed credit and they wouldn't have had the expertise to get the plane so far without being noticed. So it's someone/people who know more about the plane than terrorism, which greatly reduces their motive for doing anything with the passengers.
My guess is it was crew members who had arranged to defect, who landed the plane in some remote area (the 777 only needs 3000 feet of level runway, less if you don't plan on flying it again,) and had transportation waiting; "The truck is ours, the plane is yours, good luck.."
I think it went down in the middle of the ocean, because just think: if they got close enough to the land somewhere to get a cell signal someone on the plane would have texted someone. And if there were two terrorist they couldnt watch everyone all the time. And if they did take everybodys phone away from them there are many travelers (me too) that have two phones. Somebody would have got a message out if they ever got close to cell signal.
The best theory I've read is that there was a fire in the cockpit, which explains why they shut down all the systems, and the pilot turned toward a nearby airport.
This article explains it better than I can:
http://www.businessinsider.com/malaysia-plane-fire-2014-3
As a pilot myself, this article makes the most sense compared to all the crazy theories that have been circling all media outlets
The best theory I've read is that there was a fire in the cockpit, which explains why they shut down all the systems, and the pilot turned toward a nearby airport.
This article explains it better than I can:
http://www.businessinsider.com/malaysia-plane-fire-2014-3