Airlines and hotels play a crucial, if unwitting, role in the global human trafficking industry by providing transport and lodging to criminals...In the United States, as many as 300,000 children are trafficked annually and most are used for prostitution and pornography, according to a 2001 University of Pennsylvania study. Airlines already coordinate in a "worldwide effort among police, border control and intelligence agencies," to fight a crime that "violates the most basic precepts of human dignity," the Air Transport Association said in a statement...Busy airports are a natural distribution hub for traffickers and big airport cities become a magnet not just for adult prostitutes but also for the child sex industry, according to law enforcement authorities.