He wasn't still torturing Fockers, he was just God's lonely man. Robert DeNiro as Travis Bickle, the psycho vigilante part time cabbie in Taxi Driver (1976), is one of cinema's most engrossing anti-heroes and it doesn't take much to realize his appeal to rappers who pride themselves in taking no shit from anybody.
For Xzibit's "At the Speed of Life," it's Bickle's rehearsed lines of hate that he scribbles into a notebook like a literally mad rapper that make you pay immediate attention: "Listen, you fuckers, you screwheads, here's a man who would not take it anymore, a man who stood up against the scum, the cunts, the dogs, the filth, the shit. Here is someone who stood up." It was his first album and X to tha Z was letting the world know his mental state was that of a man who is dead-ass serious.