PETER YORK ON ADS: Screaming all the way to the check-out: NO 269: LEVI'S DOCKERS

Spy cameras are so ubiquitous that they're the basis of a whole new genre of cheap television - very cheap television. The favourite form, of course, is crime programming. And what crime on video suggests is that that type of criminal is pretty idiotic and inclined to hysteria. But somehow those muddy, jerky images of hopeless - and therefore quite frightening - people doing chaotic things are so banal, cheap and sad that it was just a matter of time before a clever, smart advertiser used them for something fashiony.

Not Levi's again! But you can't get away from it: they come up with some very diverting imagery. A few weeks ago it was Flat Eric updating their Sta-Prest sub-brand. Now it's a CCTV robbery for Dockers, another sub- brand of chinos and khakis. So we're in a supermarket and the hand-held is swinging about in a wildly unsteady amateur video way. Brief slanted shots of the aisles - it looks Low-Rent rather than Tesco or Waitrose - then a man with a balaclava and a gun. Round the corner come two super- handsome young men, one black, one white. The terrorist forces them to their knees - lots of shots of neat pants on fit frames. There's a mass of completely unintelligible action - just like real life - while the secondary baddies, stocking masks on, of course, begin stacking a tray from the shelves, shouting hysterically as they go.

It's a new 1990s characterisation of petty crims that they scream all the time, as if they were ready-made for Rampton. Somehow - and it isn't remotely clear how - their stocking masks rip and these Nutty Boys look up to see that they're on camera in close-up. And at that point we move to the greeny, muddy, jerky view of the surveillance screen. "Life's too short for things that don't last" says the strapline.

But what matters is that Levi's has captured something from the primeval slime of popular imagination. Chaos, anarchy, petty crime, hysteria and surveillance cameras; it could be you, so make sure you've got clean underwear and nice khakis.