Russian Plane Crash

This very tragic incident raises a couple of questions; particularly was it an accident or terrorist act?

ISIS are claiming they shot this plane down and time will surely tell if they did. If it was found that they are to blame, who can imagine the repercussions from Putin? What next?

Secondly, in this day and age of satellite connections, why are planes still relying mainly on the black box and not using real time communication when the technology is clearly available for instant communication?

Condolences to all those families who have lost relatives and friends in this terrible incident. Whatever the cause, their lives will never quite be the same.