Yann LeCun, now of Facebook, was interviewed by The Register. It is interesting that his view of AI is apparently that of a prediction tool:
"In some ways you could say intelligence is all about prediction," he explained. "What you can identify in intelligence is it can predict what is going to happen in the world with more accuracy and more time horizon than others."
rather than of a world optimizer. This is not very surprising, given his background in handwriting and image recognition. This "AI as intelligence augmentation" view appears to be prevalent among the AI researchers in general.
You're talking about predicting the actions of an intelligent agent.
LeCun is talking about predicting the environment. These are two different concepts.
In part of the interview LeCun is talking about predicting the actions of Facebook users, e.g. "Being able to predict what a user is going to do next is a key feature"
But not predicting everything they do and exactly what they'll type.