Los Angeles, Sep 17 (DPA) Americans have often had a reputation in much of the world as brash and rude. Now a torrent of expletives, vitriol and name-calling has left many in the US convinced that the old stereotype may be correct after all.

From Congressman's Joe Wilson's notorious interruption of a speech by US president Barack Obama with a shout of 'You Lie' to tennis superstar Serena Williams' foul-mouthed threats to a line judge at the US Open, the lack of common civility has many gentler Americans worried about the state of their society.

Their concerns only grew when rapper Kanye West jumped on stage at the MTV Video Music Awards show to protest an award to 19-year-old Taylor Swift.

West, a provocative rapper at the best of times, had been swigging from a bottle of expensive cognac before his rude interruption. Snatching the microphone from the giddy country music singer, he complained that Beyonce should have won the prize, before being booed off the stage, and very soon afterward booted out of the theatre.

He was universally condemned by his showbiz peers - some of whom used language that wasn't exactly dignified.

'You just keep amazing me with your tactless, asshole ways,' singer Kelly Clarkson wrote in an open letter to West. 'It's absolutely fascinating how much I don't like you. I like everyone. I even like my asshole ex, that cheated on me, over you.'

Even President Barack Obama chimed in, telling a reporter in an off-the-record conversation that West was a 'jackass'.

Even before the latest outbursts, a Gallup survey last month found that increasing numbers of Americans are convinced that the level of political civility is deteriorating. According to Gallup, 34 percent of Americans believe the level of discourse between Republicans and Democrats has deteriorated, up from 25 percent just a month earlier.

Others are hardly losing sleep over the apparent lack of public civility.

Some Obama opponents are printing T-shirts immortalising Wilson's infamous insult to Obama in Congress, and sending the congressman donations totalling more than $1 million.