According to a report by the International Organization for Migration (IOM), almost all migrants attempting to enter the United States are assisted by smugglers or traffickers. Human trafficking shares certain dynamics with alien smuggling, but differs in having the additional elements of coercion and/or exploitation after migrants enter the United States. Involuntary trafficking involves migrants being abducted, confined, and subjected to other human rights abuses. Voluntary migration can also involve coercion and exploitation. An example is that of women who agree to come to the United States as waitresses or dancers, but then are forced into prostitution or domestic servitude. Another example is trafficking in migrant workers who are forced to work in indentured servitude in order to pay for their trafficking fees. Many migrants are held in slave-like conditions until they are able to pay off their fees. A review of cases since 1990 found that traffickers in the United States have tended to be small crime groups and trafficking rings, gangs, loosely organized criminal networks, entrepreneurs, and corrupt individuals who victimize their own nationals. The antitrafficking strategy of the U.S. Immigration and Naturalization Service is to deter and disrupt alien smuggling at all levels of operation, including overseas, at the border, and in the interior of the United States, as well as to dismantle trafficking operations. Investigative techniques include the application of expanded asset forfeiture laws, the use of wire intercepts, the establishment of undercover proprietary businesses, and the use of the Racketeer Influenced and Corrupt Organization Act. 20 references