Why's it part of the "Rock Box" playlist?: It's one of three Madvillain tracks featured in the 2006 Boondocks episode "Let's Nab Oprah."
Which moment in "Let's Nab Oprah" does it appear?: The sequence at the end of Act 1 where dumbass wiggers Ed Wuncler III (Charlie Murphy--hold up, isn't he black?) and Gin Rummy (Samuel L. Jackson--hold up, isn't he black too?) attack a Woodcrest bookstore to carry out the episode's titular scheme, and Ed and Rummy's increasingly exasperated eight-year-old accomplice Riley Freeman (Regina King--hold up, isn't she a woman?) points out to the duo that they went to the wrong bookstore and kidnapped Maya Angelou by mistake.
The "Where's Oprah, punk?" clip from this sequence, which I tacked on to "Raid" as an intro for airplay during the "Rock Box" block, never fails to amuse me whenever I hear it. It's a hilarious sequence that also gives some nice exposure on TV to DOOM and Madlib and one of my favorite tracks off Madvillainy (because of couplets like "The metal fellow been rippin' flows/Since New York plates were ghetto yellow with broke blue writing"). The opening jazz-piano sample in "Raid" meshes well with the show's Vince Guaraldi-style original score.
Hear the Villain spit enough lightning to rock-shock the Boogie Down to Brighton.