Although drones and security robots designed to detect and prevent threats, and even take autonomous action to...

Although drones and security robots designed to detect and prevent threats, and even take autonomous action to neutralize them, have been developed, they have yet to be deployed and doing so is likely to provoke widespread public condemnation.

All very well, but it's likely that use of semi-autonomous will increase, resulting in very unbalanced between sides. Military Drones show us that one side will use a weapon on an opponent - regardless of collateral damage - when they have little chance of retaliation.
https://www.forbes.com/sites/wellsfargo/2017/10/02/wealth-vs-health-take-a-balanced-approach/#363704f32739