This lie is pretatuated by the left about the cause of the Iranian revolution but it is still a lie. The reason the Shah was overthrown was not for brutality, indeed, those who sought to overthrow him were more brutal than the Shah ever was. What fueled the revolution in Iran was the Shah pushing for a change in Iran to allow non-Muslims to serve in the government. Islamic hardliners saw this as the attempts by America at Westernizing Iran.
So what fueled the overthrow of the Shah was a push for moderation and religious tolerance.