"Five years after the World Trade Centre fell, a highly lucrative industry has been born in America - homeland security. There has been a goldrush as companies scoop up government contracts and peddle products that they say are designed to make America safe.
"The figures are stunning. Seven years ago there were nine companies with federal homeland security contracts. By 2003 it was 3,512. Now there are 33,890. The money is huge. Since 2000, $130bn (£70bn) of contracts have been dished out. By 2015 annual federal spending on the industry could be $170bn.