 Such activity is strongly assisted by the peculiar and specially trained infiltration units belonging to DIGOS that constantly enrich such reports and investigations with "inside views" of the various phenomena (hence the "special operations" part of the acronym "General Investigations and Special Operations Division" or DIGOS).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.