 Special training of such units involves classes on local slang, specific environment habits and social camouflage along with prior real life experiences as a selection preference).The activities of the DIGOS have recently been criticized, for repression of the freedom of thought protected and guaranteed by Article 21 of the Italian Constitution.Interventions carried out by the DIGOS are usually justified by an attempt to quell provocation and to ensure that incidents do not occur, according to a very broad interpretation of a law dating to 1948, which punishes "anyone who by any means prevents or disturbs a public or private political campaign meeting".