'Unpredictable' US agents fight terror
Washington -"Unpredictable" security agents, "naked" scanners at airports and air marshals have helped prevent another terror attack on the United States after September 11, a top US official said on Wednesday.
"The terrorists keep adapting and evolving to try to defeat our security... What we try to do is make sure that we are random and unpredictable in how we go about doing things," Transportation Security Administration (TSA) boss John Pistole told reporters.
"The idea is that terrorists can't go to school on what we do to try to beat us," said Pistole, who was sworn in as TSA administrator in July last year.
Teams of uniformed law enforcement officers called Vipers - for Visible Intermodal Protection Response - who patrol mass transit systems at random help deter attacks.
"We recognise that trains, buses, subways - it's a much more open architecture than aviation and there have been hundreds of attacks around the world since 9/11," Pistole told a packed auditorium at the Newseum, near the US Capitol in Washington.
Although there have been no attacks on public transportation systems in the United States, at least one plot, targeting Washington's Metro train system, was thwarted in an FBI sting operation last year.
Pistole said patdowns and controversial airport scanners that show body contours, including private parts, are "the best opportunities of detecting weapons such as that used on Christmas Day" 2009, when a young Nigerian tried to blow up a Detroit-bound airliner with explosives sewn in his underpants.
The so-called "naked" scanners provoked an outcry, with Americans saying they are an invasion of privacy. The TSA announced last month that it will phase out the show-all scanners, replacing them with devices that use software that eliminates "passenger-specific images".
The new software "will auto-detect items that could pose a potential threat using a generic outline of a person for all passengers", the agency said.
The TSA has also come under fire for its "enhanced" patdowns - in which a TSA agent touches a passenger's private parts - required for people who refuse to pass through the scanners.
According to media reports, small children have been given enhanced patdowns and a breast cancer survivor was asked to remove a prosthetic breast by a TSA agent after a patdown.
But Pistole said the number of times the TSA has mishandled an airport screening was a drop in the ocean when compared to the 1.8 million travellers who pass through US airports every day.
TSA agents have "screened nearly six billion people since 9/11, and any time people engage with others six billion times, there's bound to be some things where we could have done a better job", he said.