Latrocinium (from Latin latrone, ultimately from Greek latron, "pay") hire) which meant primarily a mercenary, or hired soldier, had the same meaning as miles. Latrocinium applied to a war that was not preceded by a declaration of war under the Roman laws; it was also applied to the guerrilla warfare used by the enemies of Rome.  In the Middle Ages, latrocinium was a war without just cause, or piracy.  Plato and Aristotle considered that latrocinium was a way of life like fishing or hunting. 
The third Council of Sirmium in 357, second Council of Ephesus in 449, Council of Hieria in 754 and Synod of Pistoia in 1786 were each described by their opponents as a latrocinium. Some also regarded the fourth Council of Constantinople, meeting in 879-880, in the same way.
Some conservative Catholics, including sedevacantists and conclavists, regard the Vatican II as a Latrocinium, given its alleged role in a fundamental revision of Roman Catholic rituals and (they claim) belief, notably the replacement of the Tridentine Mass by the Mass of Paul VI (the vernacular Mass, which sedevacantists describe as the Novus Ordo Missæ or "New Order Mass" and thus refer to the post-Vatican II Catholic Church as the "Novus Ordo Church") with the resulting greater participation of the laity in the ceremony and the reordering of church sanctuaries. They argue that many of the fundamental documents of Vatican II contradict earlier Church dicta and papal bulls, including the Quo Primum Papal Bull of 1570 and the Syllabus of Errors of Pope Pius IX in 1864.
However few mainstream members of the Roman Catholic Church, no senior members of the hierarchy and none of the popes during or after the Council (Popes John XXIII, Paul VI, John Paul I, John Paul II and Benedict XVI) accept the belief that Vatican II was a Latrocinium. Vatican II, its documents and the Mass of Paul VI remain central to modern day Roman Catholicism.