Are the robots going to waste everyone all at one time? I think after the first few murders the humans might get a clue.
And once the humans were all snuffed, who would generate the power to recharge the bots? Sounds like a scenario for a century from now, when bots might actually be doing and running EVERYTHING.
That will not happen. Christ will return in a very short while. The generation that witnessed the rebirth of Israel in 1948 will not completely pass from the scene before Christ returns.
IG-88