Why did the Iranian's overthrow the shah in the late 70s?

they had more freedom under the shaw then they do today . i don't know what kind of leader the shah was but he could not have been as bad as what the iranians are living with now . seems like the iranians not only got reid of the shah but they lost there freedoms now they live under a dictatorship . i cant help but to wonder if young iranians are not asking there parents why did you do this to us .