They are there. There are highly classified and they were on Flight 370, being continually monitored by military and security forces tasked specifically with preventing commercial aircraft from being used as weapons. Read more...
Flight 370 Mystery SOLVED! Israel & US Have It At Diego Garcia Along With MH370 Replica Plane PROOF (Video) | Conspiracy Theories
This is an interesting theory. There definately seems to be something going on. Diego Garcia has just cancelled leave for soldiers based there, the plane still hasn’t been found and it just so happens they are getting blackbox pings right before the battery is suppose to die. How convenient.Missing MH370: Ex-Malaysian PM hints at CIA conspiracy and claims 'someone is hiding something' - Mirror Online
Mahathir Mohamad argues the missing plane could have had its MAS markings removed and that the US government agency knows what happened