An 18-month investigation by Reuters has revealed the market for "private re-homing," in which adoptive parents advertise their adopted children online, often signing the kids away to new parents with no legal oversight. About 70 percent of the kids being advertised were adopted from overseas, affording them even fewer legal protections, and at least one child ended up in the hands of a child pornographer.

US law allows parents to transfer custody of their children to other adults using a simple signed agreement called a "power of attorney." The provision is meant for temporary situations, such as turning a child over to a trusted relative if the parents have to travel. But Reuters reports it is being used to quietly transfer adopted children to new homes — and frequently to complete strangers — without involving courts, lawyers, or social workers.

This unsupervised transaction is legal, except when the child is crossing state lines, reports Reuters. Certain aspects of the transaction, such as advertising for adoption without a license, may be illegal in some states. But even then, the law is rarely enforced.

In some cases, the adopted child is violent or dangerous and the parents are at their wits' end. There are scant options available for re-homing adopted kids, and many are costly. In other cases, the parents simply decide they don't want the kids anymore. One couple that adopted a eight-year-old girl from China and decided after five days that "we do not believe we can provide the full attention that she needs and deserves."

Adoptive parents sought new homes for their kids on Yahoo message boards and Facebook, Reuters found

Reuters found eight Yahoo message boards and one Facebook group where these kinds of transactions were taking place. Yahoo has already removed at least one of the message boards after being informed of its existence by Reuters; Facebook declined to remove the group, saying "the internet is a reflection of society." That's a dark thought considering the postings reproduced by Reuters, some of which read like ads for pets, boast of children as "attractive" or "eager to please," and contain admissions like "we do truly hate this boy." And there are even more revelations to come; Reuters has posted only the first two installments of the five-part series.