Oh I didn't mean 'violated', but 'no longer work as intended'. It's been a while, but I think there were cases where the robot was paralysed because of conflicting directives from the three laws.

If I remember correctly, there was a story about a robot that got stuck midway between two objectives because it was expensive and so its creators decided to strengthen the law about protecting itself from harm.

I'm not sure what the cautionary tale was intended to be, but I always read it as "don't give unclear priorities".

Yeah, the general theme was the laws seem simple enough but the devil is in the details. Pretty much every story is about them going wrong in some way (to give another example: what happens if a robot is so specialised and isolated it does not recognise humans?)