Every year, some 20,000 young adults come to the U.S. on special visas to work as an au pair, caring for pre-school children in the home. Most of the time things work out fine. But when problems do arise, someone has to enforce the rules. Au pairs and critics say the State Department and au pair recruiting agencies are failing to oversee the system. Vero Balderas Iglesias reports in Part 3 of "The Perils of Au Pairs."