Deadlier drones are coming

"There's no plan for humans to be totally out of the loop," says Ryan Calo, a Stanford University researcher. "But there are pressures that create incentives for ever more autonomy," he adds.

Military robots are potentially indiscriminate,” says Patrick Lin, another Stanford researcher. “They have a difficult time identifying people as well as contexts, for instance, whether a group of people are at a political rally or wedding celebration.”