Transcript for Sex Trafficking Spike Looms in Super Bowl's Shadow
Reporter: These flight attendants and airport workers, training to recognize sex traffickers among the thousands heading to the super bowl. Criminals, transporting women, and children to New York, against their will. Not for the biggest weekend in football. But for the biggest weekend in prostitution. Any event where there's going to be a lot of men, a lot of money and a lot of alcohol, there's going to be a an increase in demand for sex. Reporter: Ads jumped by 50% over the weekend. Expected to triple by Sunday. So, today, a counterattack. New billboards in times square. At Madison square garden. And videos played in major train and bus stations. It's time to open our eyes. Reporter: These are places we know that victims end up. They will see these billboards. They know someone is out there to help them. Reporter: The training works. In Boston, a child prostitution ring smashed. 86 children freed after an airline worker noticed a man traveling with two crying children. We caught a dozen. Reporter: All because the airline worker had been trained to look for tell tale signs. Someone who doesn't have control of their own I.D.S. Someone appearing under the control of another. Someone who looks lost. It's better to be a little nosey and be wrong than to let a victim walk out of your life. Reporter: Airlines, amtrak and hotels on the lookout this super bowl weekend, most unaware of the big game. Jim Avila, ABC news, Washington.
This transcript has been automatically generated and may not be 100% accurate.