This article from the Atlantic explores the practice of "second-chance adoptions," children who were already adopted and whose adoptive family no longer wishes to parent them, in the United States. According to the article, "between 1 and 5 percent of U.S. adoptions get legally dissolved each year." The article shines light on a Facebook page where children who are available for re-adoption are "advertised."
"Legally speaking, adopted children are recognized as no different from biological children. And for this reason, parents who opt to put a child up for re-adoption are doing nothing more legally complicated than any parent who puts a child up for adoption. But children who end up in need of adoption a second time will have their lives deeply disrupted, and the experience could leave them with lifelong doubts about their worth."