I don't know about pitching children off cliffs, but the Italian branch was repudiated by Waldes himself before his death.
Accounts of atrocities committed against Waldensians in Italy are widely available. Children were pitched off of cliffs; that fact is not under controversy. It was immortalized in poem and song in England, and even stirred Cromwell into attempts to extract vengeance. It was truly notorious during the era in which it occurred. I can refer you to the head of the Waldensian Church here in America if you'd like. He's just up the road in Valdese, NC.
Seeing as how the French Waldensians in Lyon, known as "The Poor of Lyon," had been wiped out by the Catholic Church and the survivors fled to Italy themselves, including Peter Vaud/de Vaux/Valdez/Waldes/Waldo, I see little reason to accord such a statement much credence. The Italian Waldenses, "The Poor of Lombard," were the only Waldensians left, and they themselves were decimated over two centuries after the death of their founder, in the attack that I described. They came here to North Carolina to find some peace and to worship unmolested, just a little over a century ago.
The Waldenses were characterized from their earliest beginnings by lay preaching, voluntary poverty and strict adherence to the Bible. Peter Waldo commissioned a cleric from Lyons around 1180 to translate the Bible, or parts of it, into the vernacular, the Arpitan (Franco-Provençal) language.
In 1179, Waldo and one of his disciples went to Rome. They were welcomed by Pope Alexander III, and by the Roman Curia. They had to explain their faith before a panel of three clergymen, including items which were then debated within the Church, such as the universal priesthood, the gospel in the vulgar tongue, and the issue of self-imposed poverty. The results of the meeting were inconclusive, and Waldo’s and his followers’ ideas, initially regarded with suspicion, were condemned at the Third Lateran Council in the same year, though the leaders of the movement had not been yet excommunicated.
The persecution of the Waldenses was one of the more shameful episodes in Catholic history. There was no reason for this. They'd been permitted to live in peace by the Duke of Savoy for centuries, and then came what had every earmark of a pogrom against them.