The bad thing for me is, robots in such riots could be soon reality. But soon is relative.. We have such a pace of development in fields which are supporting each other like

• AI
• robots
• quantum computing
• autonomous driving
• deep learning
• nuclear fusion
• blockchain
• nanotechnology
• mobile computing

Everything gets more intelligent, faster, much cheaper in large scale. It is said we live in times of exponential growth and nearing us the singularity which no one can describe exactly. But the development is so fast that we speak today of probabilities of the usage of robots in such scenarios and months later maybe in Japan or China that is just reality.

A robot could be

• more reliable not driven by emotions
• stronger to reduce the number of units for controlling a riot
• much cheaper need no salary, just initial investment and some maintenance
• intelligent with swarm intelligence supported by air and ground units

..and the controlling people behind disconnect their emotions after pushing the red button.. because the robots did.. and the robots need no cure of souls after harmed or killed people.

What holds people back today i think is the high price for such machines and that the technology is still far away to act independendly. For me it's more a question of time not if that happens. It could be 50 or 10 years, or just 5.. but i think for the dystopia it needs much time and i hope that we as mankind are conscious of each step in such directions and to avoid a world completely controlled by machines as i wrote in a post about robots and ai long time ago.