Prostitution law
However, sex worker activists and organizations distinguish between human trafficking and legitimate sex work, and assert the importance of recognizing that trafficking is not synonymous with sex work. The Sex Workers Alliance Ireland organization explains: "victims of human trafficking may be forced to work in industries such as agriculture, domestic service as well as the sex industry. It is critical to distinguish human trafficking, which is a violation of human rights, from voluntary migration." The Open Society Foundations organization states: "sex work is done by consenting adults, where the act of selling or buying sexual services is not a violation of human rights. In fact, sex workers are natural allies in the fight against trafficking. The UNAIDS Guidance Note on HIV and Sex Work recognizes that sex worker organizations are best positioned to refer people who are victims of trafficking to appropriate services."
Trafficking of children
The Optional Protocol on the Sale of Children, Child Prostitution and Child Pornography is a protocol of the Convention on the Rights of the Child, formally adopted by the United Nations in 2000. Essentially, this protocol formally requires states to prohibit the sale of children, child prostitution, and child pornography. According to the International Labour Organization, sexual exploitation of children includes all of the following practices and activities: 
Though measuring the extent of this practice is difficult due to its criminal and covert nature, the International Labour Organization estimates that there are as many as 1.8 million children sexually trafficked worldwide, while UNICEF's 2006 State of the World's Children Report reports this number to be 2 million. The International Labour Organization has found that girls involved in other forms of child labour - such as domestic service or street vending - are at the highest risk of being pulled into commercial child sex trafficking. Likewise, Kendall and Funk justifies how “young girls age 12 and under are malleable and more easily trained into their prospective roles as prostitutes, and because virginity is highly prized by certain consumers willing to pay a premium” (31).A variety of sources, including the I.L.O, and scholars Erin Kunze and D.M. Hughes, also contend that the increased use and availability of the Internet has served as a major resource for traffickers, ultimately increasing the incidence of child sex trafficking. In fact, in 2009, Illinois Sheriff Thomas J. Dart sued the owners of Craigslist, a popular online classifieds website, for its "allowance" and "facilitation" of prostitution, particularly in children. In response to public and legal pressure, Craigslist has since blocked all access to its "Adult Services" section.