A pop singer exposes herself on national television. A football star head-butts his opponent in the World Cup soccer final. Canada Day revellers relieve themselves on the National War Memorial.

These incidents over the last 18 months -- in the United States, Europe and Canada -- might be seen as unusual, even isolated. In a sense, though, they are simply part of a reign of vulgarity and coarseness today that engulfs us like an oil spill.

Janet Jackson's "wardrobe malfunction" at the Super Bowl was called an accident, but then again, it may well have been intentional.

The Entertainment Channel in the United States recently ran an hour-long program on celebrities, delighted to attract the publicity, who are dressing provocatively.

Zinedine Zidane's attack isn't unusual in sports. Ten years ago, basketball star Dennis Rodman head-butted a referee. Nine years ago, boxer Mike Tyson bit the ear of his opponent. In hockey, six years ago, Marty McSorley of the Boston Bruins hit another player with a stick; two years ago, Todd Bertuzzi of the Vancouver Canucks punched an opponent in the side of the head.

The miscreants who relieved themselves on Canada Day were not only drunk, they were ignorant.

There is a good chance that they'd never even heard of the National War Memorial, which wouldn't make them any different from many of their contemporaries. It doesn't excuse their behaviour, but it may explain it.

Why should this contagion of head-butting, public undressing and urinating surprise us?

The cult of celebrity, the spread of scandal, the celebration of sleaze, the decline of sportsmanship, the rise of trash talk and the erosion of manners are all at work today.

Vulgarity diminishes us. It is everywhere -- in dress, in speech, in sports, in popular music, on the airwaves, in newspapers and books.

Styles change from year to year, of course, but garishness in dress continues to be fashionable. Underwear worn above trousers in young men; exposed bra straps and thongs in young women. It seems to be de rigeur, no matter how cheap it looks.

You saw how far we had fallen when Bill Clinton was once asked whether he wore boxers or briefs. Or when you read the lurid and obscene messages on T-shirts.

Our language has become less polite. The general loss of honorifics means students address professors by their first names, and dental hygienists do the same with patients twice their age.

Then there is the epidemic of expletives. It used to be that you couldn't say "bullshit" in decent company and you couldn't write it in newspapers without ellipses.

Now such language is everywhere, routinely appearing in the titles of bestselling books and in some newspapers' letters to the editor and news reports, without a warning or apology.

In this kind of a climate, nothing we hear or see should surprise us anymore.