Sufism
Historically speaking, orthodox Islam, especially fundamentalist groups like the Wahhabi and Salafi have been the most intolerant and violent against what they think of as 'Deviant Sufism'. In the past centuries, severe persecution has been carried out by them against the Kharijites, the Ismaili Shia cult (sometimes termed the 'Assassins'), the Ahmadiyya movement and several other groups and individuals with Sufi-like mystical tendencies and practices. During the time of the later Mughal Empire in India, even the early gurus of Sikhism were persecuted by orthodox Islamic mullahs (theologians) since they had chosen to incorporate some of the ideas and poetic verses of the Sufi saint Baba Farid into their holy scriptures. In more recent times, over the last two decades, considerable persecution has been made of the spiritual reformer and sage Riaz Ahmed Gohar Shahi and his followers in Pakistan. He was opposed and threatened and forced to flee the country and his books banned there, and anyone publicly supporting him is liable to immediate arrest.