The biggest travel threat facing the world now is passport fraud, according to the chief of Interpol – the millions of stolen documents that could be used by terrorists or criminals to travel worldwide. Airport body scanners, embraced by many in the aftermath of the attempted Christmas Day airplane bombing, are a misguided solution to travel threats, Interpol Secretary-General Ronald K. Noble told The Associated Press in an interview Thursday night. “The greatest threat in the world is that last year there were 500 million, half a billion, international air arrivals worldwide where travel documents were not compared against Interpol databases,” he said on the sidelines of the World Economic Forum, where 2,500 business and political leaders are gathered in this Alpine resort. “Right now in our database we have over 11 million stolen or lost passports,” he said. “These passports are being used, fraudulently altered and are being given to terrorists, war criminals, drug traffickers, human traffickers.” The solution, he said, is better intelligence, and better intelligence sharing, among countries. “You don't know the motivation behind the person carrying the passport,” he said. If you're a terrorist, he said, “Are you going to carry explosives that are going to be detected? No.” Many US airports use the body-scanning machines and airports in other countries are adopting them after Nigerian Umar Farouk Abdulmutallab allegedly tried to detonate explosives hidden in his underwear Dec. 25 on the Detroit-bound flight. But Noble questioned “the amount of money and resources that go into these (body-scanning) machines.” He cited a case two weeks ago in a Caribbean country where five people were arrested carrying European passports, but were caught after they were found to be carrying stolen passports – one stolen back in 2001. The five had “definite links to crime, organized crime, human trafficking but no definite links to terrorism,” he said, though he wouldn't name the country.