Wikipedia
Pistolerismo (from Spanish pistolero, gunman) refers to the practice, used by Spanish employers during Alfonso XIII’s reconstruction crisis, of hiring thugs to face syndicalists and notable workers. The workers replied in turn by hiring their own gunmen.
In the end, pistolerismo caused the death of 200 workers and 20 employers’ gunmen.
Pistolerismo primarily affected Barcelona's urban and industrial proletariat, which was getting active and making an increasing number of strikes motivated by the Confederación Nacional del Trabajo (CNT), a Spanish anarcho-syndicalist trade union, though there were similar actions in other Spanish cities. After experiencing the CNT’s great power in Labor disputes, the employers decided to strike back through violence, and the employer-worker clash degenerated into white pistolerismo (white terrorism by the employers), replied to in turn by anarcho-syndicalist terrorism. Employers, politicians, the clergy and the forces of order on the one hand, and syndicalist leaders and lawyers were the target of these two kinds of terrorism.
The employers replied by closing several factories, dooming a lot of workers to unemployment and famine. The employers were helped by “Yellow” Trade Unions, or “Free” Trade Unions, such as the Sindicat Lliure, which provided scabs to supply the workers that were being punished. They also forced the Government to stop, by any means, the increasing role of anarcho-syndicalism in Spain. The Government chose General Martínez Anido as Civil Governor of Barcelona. He protected the white terrorism while putting down syndicalism by applying the “escaping law”, a process that consisted of telling prisoners that they had just being released, in order to execute them moments later for “attempting to escape from prison”.
White gunmen assassinated, among many others, famous syndicalists such as Pau Sabater in 1919, Evelio Boal in 1921, Salvador Seguí “El Noi del Sucre”, Francesc Comes in 1923, and lawyers such as Francesc Layret in 1920.