The problem of stolen large commercial passenger jets is not new. It's happened in Africa before (as in, one day a 727 that was parked out-of-the-way somewhere isn't there when airport workers go looking for it).

The major problem with the hijacked-for-future-nefarious purposes is: now what? There aren't too many places an unexpected 777 can land and hide unnoticed, especially with a major search for a 777 underway.

The antagonist in movies is always an Evil Genius, but it real life they're often Evil Morons. Anyone trying to steal a 777 probably falls in the latter group.