Silvia Avalos, a hairstylist, and her husband, Jose Luis Avalos, a busboy, are among the people Mancera is talking about. They were tired of spending their money on rent each month but didn't want to use fake Social Security numbers to buy a home. After friends told them they could buy legally, they found a two-bedroom condo northeast of San Francisco for $280,000. They moved in as soon as escrow closed. "We saw it as an investment," Silvia Avalos said. "While you are here, you have somewhere to live that is yours. And if you return home [to Mexico], you...