purpose of having their children born as american citizens. >> reporter: this court affidavit claiming the website you win usa vacation resort was used to attract pregnant chinese women who authorities claim paid 15 to $50,000 for housing, food and visas that allow them to be here legally. the ring leaders accused of pocketing hundreds of thousands of dollars could face criminal tax fraud, money laundering and conspiracy charges. federal agents estimate 400 children born at one hospital alone. this is one of the apartment complexes raided. authorities aren't expecting to make any immediate arrests. these pregnant women now considered material witnesses. many said to be scared during the raids. with paramedics on hand just in case they went in to labor. brandi hitt, abc news, rowland heights, california. >> talk about crazy, weird twist of fate, one of them, one of these companies set up offices across from the feds, irvine