America has spent billions of pounds on faulty anti-terrorism screening equipment, which they now have to replace.
The troublesome devices include explosives detectors triggered by Yorkshire puddings and nuclear weapons monitors which are set off by bananas.
Since the September 2001 attacks, £2.4 billion has been spent on equipment to monitor airports, ports, mail sorting offices and border posts. But most of the money has been wasted, the New York Times reported yesterday.
The authorities are now spending billions more to buy new equipment or modify earlier purchases. Among the problems were radiation detectors unable to differentiate between nuclear weapons, cat litter or bananas.
Some chemical weapons monitors went off 36 hours after an attack, while mail screening systems picked up anthrax traces but nothing else. "Everyone was standing in line with their silver bullets to make us more secure after September 11," said Col Randall Larsen, a former government adviser. "We bought a lot of stuff off the shelf that wasn't effective."
In one case, airport authorities bought 1,300 screening machines, each costing more than £500,000, to detect explosives by assessing the density of objects.
But many objects, from shampoo bottles to Yorkshire puddings, have similar densities to explosives, triggering the alarm in up to a third of all luggage.
A spokesman for the Transportation Security Administration said even poorly functioning devices provided some deterrence to terrorists.
Christopher Cox, the Republican chairman of the House of Representatives homeland security committee, said that after the terrorist attacks, the government showed its commitment by spending more money as rapidly as possible.
He said: "That brought us what we might expect, which is some expensive mistakes."
From the Telegraph.