Rights activists, under the umbrella of the Justice Development and Peace commission, march against the illegal human trafficking and countrywide violence during a protest march on March 18, 2017 in Lagos.
Prosecutors often also work closely with the Department of Labor, which has sworn law enforcement officers that look into Visa fraud. According to a report produced by Polaris, a top human trafficking research group, traffickers often commit Visa fraud as part of their scheme.
Trafficking can be lucrative and those involved often finds ways to be nimble to elude law enforcement. For example, massage parlors that are shut down by law enforcement might open again under a different name but with the same connection to a human trafficking business, according to trafficking expert Kimberly Mehlman-Orozco.
According to Polaris, there are over 9,000 illicit massage businesses in the U.S. that generate revenues around $2.5 billion.
The July operation involved more than 400 law enforcement agencies, and agents set up fake dates in order to identify possible victims, according to the FBI.
Agents relied on intelligence from the National Center for Missing & Exploited Children (NCMEC) to identify young runaways, missing kids and juveniles.
Additional reporting by ABC News' Karma Allen