Environmentalists and videoconferencing vendors alike keep telling us we need to fly less to reduce our carbon footprints. Many argue for higher fuel taxes and fewer subsidies to airlines, but could they be missing a trick? Perhaps all they need to do is push for even more "security" at airports...

Flying to inspect Novell's SUSE development labs in Nuremberg recently, I was reminded just how much the folk who run today's airports seem determined to put themselves out of work.

It started at Heathrow, where I discovered a queue for security that snaked the entire length of Terminal 3, before curling back on itself and winding all the way back again.

It being a somewhat early flight, I'd brought breakfast with me - a pot of yogurt and an apple - so when a chap came by offering clear plastic bags for one's cosmetics (and yes, cosmetics were the only items he called out), I thought I'd save trouble by putting my yogurt in one.

"No yogurt allowed," said the lady checking the plastic bags. I was incredulous - but that was that. Yogurt was banned and I could either bin it or eat it there and then (I chose the latter).

Of course, the whole clear-plastic-bag thing is a charade anyway, played out in the hope that we cattle will believe that our overlords care about our security. But a ban on yogurt? What do they think we'll do with it - hijack the plane by threatening to pour it over the stewardess's head??

And if someone claims it's because it has the same X-ray signature as Semtex, I won't believe them any more than I believe that mixing binary liquid explosives on-board is a practical proposition.

It's not just Heathrow either. Later in the day at Frankfurt airport I encountered metal detectors set so sensitively that they'd probably have picked up a penny. Still, at least pennies really are a credible threat - as long as you can open the aeroplane window to drop them on passers-by, 10km below.

Well, if the aim of it all really is to put me off air travel, it's working.

Incidentally, does anyone know what the claimed purpose of airport metal detectors is these days? Any sensible hijacker will choose ceramic knives and plastic handguns over metal, and they're not going to pick up heroin or Semtex - that's why chemical residue sniffers were invented.