There's a great, great article in this month's Mother Jones by Elizabeth Larsen titled, "Did I Steal My Daughter? The Tribulations of Global Adoption". I encourage you all to read it; it's a terrific piece. An excerpt from the article:

Is it ethical for an adoptive parent to push for information about her child's birth family? Or should that be a decision left to the adoptee? And what about the birth family's right to privacy? "You can't compare an open adoption in the U.S. with an open adoption process internationally," says Susan Soon keum Cox, vice president of public policy at Holt International, an Oregon adoption agency whose founders launched transnational adoptions in the United States. The child of a Korean woman and a British soldier, Cox, who was adopted in 1956, found her Korean half brothers when she was an adult. Yet she cautions against too-hasty birth family searches. "The stigma of adoption in many countries is still very powerful and very real. Women place their children for adoption and slip back into society. It's a very different thing than the acceptance of single parents and adoption in the U.S." In China, currently the greatest source of transnational adoptees—6,493 U.S. "orphan" visas were issued to Chinese adoptees in 2006—relinquishing a child is illegal, and families sometimes abandon their children to avoid running afoul of the one-child policy; birth mothers found to have done this can face prosecution.
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Openness, Smolin notes, would also make it harder for parents to think of adoptions as "rescuing" children. "There are cultural reasons why people give up children for adoption," he says. "But when you have a situation where money alone, in relatively small quantities, would allow the birth family to keep the child—under current law you are allowed to take the child and spend $30,000 when $200 would be enough to avoid the relinquishment."