In 1999, Rage Against the Machine played live on Letterman. The key word being “live.”
This is a band that pushes the envelope. Their songs are known for being politically-charged. So David Letterman shouldn’t have been surprised when Zach De La Rocha flipped the bird. On live TV.
It’s one of late night television’s greatest music moments.
WATCH (skip to 1:33 for the bird flip):