But I ain't never crossed a man that didn't deserve it
Me be treated like a punk, you know that's unheard of
You better watch how you talking, and where you walking
Or you and your homies might be lined in chalk
~ Coolio explaining a gangster's life style in the song, "Gangsta's Paradise."

Gangsters are criminals who lead a life in the "underworld"; that is, raised in an environment filled with gangs, drug dealing, gun running, chop shopping, and poverty.