United broke Dave Carroll's guitar and closed the claim — he answered with a hit song

On 31 March 2008 Dave Carroll, a Canadian singer-songwriter with the band Sons of Maxwell, flew United from Halifax to Omaha via Chicago. At O'Hare a fellow passenger watched baggage handlers throwing guitars on the tarmac; Carroll's $3,500 Taylor guitar came off the flight broken. The United employees he alerted on the spot showed 'complete indifference', and afterwards the airline denied his compensation claim because it was not filed within the standard 24-hour window. Nine months of exchanges ended with a firm 'the matter was closed'.

Carroll had warned United he would write a song; the warning went nowhere. On 6 July 2009 he posted 'United Breaks Guitars', a $150 video, to YouTube: 150,000 views in a day, nearly 2.5 million within five days, more than five million by mid-August. The stock dipped about seven percent in the days after the video spread — reports of a ten percent, $180 million fall circulated but later price data showed a much smaller move — and the song became the defining example of consumer revenge in the social-media age.

United's managing director of customer solutions Rob Bradford apologised, asked permission to use the video for internal training, and settled; Carroll donated the settlement to the Thelonious Monk Institute of Jazz. Taylor Guitars' owner Bob Taylor gave Carroll two guitars. United said it hoped to learn from the incident and change its customer-service policy; the episode became the customer-service case study of its era.