Isaac Asimov's first law of Robotics:
"A robot may not injure a human being or, through inaction, allow a human being to come to harm."
When I read this in the mid 1980s, as a teen Sci-Fi fan and a young computer programmer, I was stumped.
The clause that I found the most difficult was, "through inaction". What this means is - if there's a toddler in a room that is dangerously close to a stairwell or a balcony, your robot vacuum cleaner should spring into action and keep that child safe.
This meant that the robot had to be:
1. Constantly Powered on.
2. Have video camera capabilities.
3. Constantly watching the room.
4. Constantly processing the input video stream to determine whether a human was in danger, in the camera's field of view.
In 1984, this was a tall order. My ZX Spectrum+ had only 48 Kilobytes of RAM. It had no video camera. Processing a live video feed intelligently was way beyond the capabilities of that machine, and of most computers of that time.
Today it's possible to achieve this capability with contemporary hardware and software. However, this means that we briefly turned into a surveillance state, with machines hypervigilantly watching us, to keep us safe, and to keep the watchmen safe.