Warning (Green Day song)

"Warning" is a song by American rock band Green Day. It is the second single and title track from their sixth album of the same name. Billie Joe Armstrong has said that the original concept was to create a song whose lyrics were made up of all signs and labels, and the idea grew from there. The song was a number-three modern-rock hit in the United States. The song also entered the top 40 of the UK Singles Chart.

Composition
This is the first Green Day song to feature a tremolo effect on the guitar—an effect used prominently in the 2004 single "Boulevard of Broken Dreams". It has been noted that the song's main guitar riff bears strong resemblance to the Kinks' song "Picture Book".

Music videos
"Warning" has two music videos. The first and main music video premiered on MTV in January 2001. It was directed by Francis Lawrence and shows the life of a rather oblivious young man who does dangerous, socially unacceptable and trivial things during his day examples being rubbing soap in his eyes, swallowing toothpaste, running into moving traffic and crossing police tape. His punch-in card reveals his name to be John Earle. The second music video features the recording and touring of the song and album edited together.

Live performances
Despite being included in the band's greatest hits albums International Superhits! and God's Favorite Band, as well as appearing as a playable track in the video game Green Day: Rock Band, the band did not perform the song live for 21 years since 2001, until it was performed during a warm-up show before their performance at the 2022 Lollapalooza.

Track listings
US 7-inch single
 * A1. "Warning"
 * B1. "Scumbag"
 * B2. "Outsider"

UK CD1
 * 1) "Warning" (album version) – 3:42
 * 2) "Scumbag" – 1:44
 * 3) "I Don't Want to Know If You Are Lonely" – 3:08

UK CD2
 * 1) "Warning" (album version) – 3:42
 * 2) "Outsider" – 2:17
 * 3) "Suffocate" – 2:57

UK 7-inch single
 * A. "Warning" (album version) – 3:42
 * B. "Suffocate"

Australian CD single
 * 1) "Warning" – 3:42
 * 2) "Minority" (album version)
 * 3) "Scumbag" – 1:44
 * 4) "Outsider" – 2:17

Japanese CD single
 * 1) "Warning" – 3:42
 * 2) "Scumbag" – 1:44
 * 3) "Outsider" – 2:17
 * 4) "I Don't Want to Know If You Are Lonely" – 3:08