I used to have this discussion with libertarians. They always argued that the free markets are efficient. I told them, if the omnipotent free markets always kno

I used to have this discussion with libertarians. They always argued that the free markets are efficient. I told them, if the omnipotent free markets always know and tell you what is good for you, and you supposedly follow that advice (if the system is to be efficient), how is it freedom?