Science fiction helps sell newspaper well. This is why such fantastic stories come up regularly I guess, especially during the Summer.
I followed a military presentation lately on RPVs control.
We will not talk about the actual "failure" rate , which in PRV terminology means "crashed and/or gone to the enemy " which are in two digits figures , and even 1 out of 3 for some types.
What was interesting for us, ATC, was the lack of security of the control links. In fact one clever hacker in the USA and one in France have recently took control of some UAvs for brief periods to show how vulnerable the systems are and how easy it is to get "inside" the control systems.
That is the main issue today, and why, among other things (*) , outside of military, you are unlikely to see large civil PRVs with people or valuable cargo inside flying around I would say .
Solution : none unless they (and we) use something else than radio frequencies to transmit data. Not sure what it can be. They did not tell us.
So, for me, an hijacked civil airliner with pilots on board being shut off " and then controlled from the ground is pure fantasy. There are far more risks in having such device than without it.
(*) the other issue is cost/benefits as pointed out repeatindly by Huck here, Operating an old 747 or even a new 777F with 2 guys in front is still, and by far, a lot cheaper than using an unproven design with a 2 digits failure rate.