Why were anabaptists considered by both catholics and protestants to be dangerous radicals?

Anabaptists were part of the radical refore movement in the 16th century Europe. Hutterites, Amish and Mennonites are direct descendants of the anabaptists. They required baptismal candidtes to make their own faith confessions, and as a result forbade the baptism of infants. They were persecuted by both the roman catholics and the magisterial protestants.