The first Counselor to Joseph Smith in Nauvoo was William Law. William and his brother Wilson and their families were converts from Canada who joined the Saints in Nauvoo late. They had considerable wealth and came into favor with Joseph and Hyrum and even defended them against accusations of polygamy. Until that is, they learned for themselves that many members in Nauvoo were implementing it.
Then, at significant risk to themselves and their livelihoods, William, Wilson, and others turned and condemned the practice of polygamy in their publication Nauvoo Expositor. Joseph and Hyrum responded by publicly slandering William and Wilson, accusing them of adultery while aggressively denying their involvement in polygamy/polyandry.
In modern times, the Church disciplined and even excommunicated six “intellectuals” now known as the “September 6” in 1993 primarily for disclosing unflattering aspects of Church History.