The Untouchables (1959) : 3x4

In the years following WWI, there was a flood of European immigrants into the USA. In the early 1920s, the 6 Genna brothers, place of origin Sicily, were headed to Chicago. The Genna brothers are nothing but a gang of bullies, and in a few short years they are the ruling lords of Little Italy, an Italian neighborhood in Chicago. One night, as the 6 Gennas are beating up a street vendor, Agent Enrico Rossi whales into them. The leader, Mike Genna, asks if he knows who they are; Rossi says, ""Yeah, the Genna brothers-- one rat with 6 heads!"" Mike Genna says that Enrico Rossi is Italian, just like them; Rossi says he's ashamed.