What do the Piebalds claim about the Witted in the novel, The Golden Fool?

Piebalds claim persecution by the Witted, or magical people, of the Six Duchies. In actuality, the Piebalds are a rebel group who want to separate and seize power. They hate the Witted Bastard, FitzChivalry Farseer (Badgerlock), who was seen as an obstacle for inheriting the throne.