Everyone loves a David and Goliath story, where the little guy takes on the big guy and wins. But when it comes to felling corporate giants, social media makes a much better weapon than a sling.

One such latter-day David, David Caroll, a country and western singer, recently landed a social media blow to United Airlines after their sloppy baggage handlers damaged his beloved $3,500 guitar.

Utilising another lethal online weapon, known as humour, he recorded a song and video recounting his year-long struggle to get compensation for what he calls “a vicious act of malice” at O’Hare International Airport in Chicago last year.

He exacted revenge by uploading it to YouTube (http://bit.ly/z2GU5), making his band an overnight success when it gained a five star rating, and  had more than four  million views to-date.

Due to popular demand, the track is now available for download on iTunes too!

It’s a very modern nightmare for any CEO – a social media smear campaign that goes viral. But how best to handle such online PR disasters, assuming the facts are correct?

A spokeswoman for United said the video “has struck a chord with them”. While they agree that this should have been fixed much sooner, “Dave’s excellent video has provided United with a unique learning opportunity that we would like to use for training purposes to ensure all customers receive better service from us.”

Sorry we’ll train our staff better – is the right answer.

So much better than Ryan Air’s  ‘all bloggers are idiots’ approach to online PR, I wrote about a few weeks ago (http://bit.ly/F4Aqg).

United has a long history of suffering from bad online PR.  Mostly at the hand of one man, Jeremy Cooperstock, who since 1996 has run the ‘gripe site’ called untied.com, a common mistyping of  united.com, detailing its history of customer service crimes.

Their disrespect for one man’s guitar has already been added to the site.

So next time you are ‘tired of excuses or chasing call centre wild gooses’ (to steal a line from David’s song), threaten social media revenge: it should bring any corporation to its knees.