Secure Communities started as a pilot enforcement program in a handful of counties in 2008.
Today, most of the country is signed onto it, despite growing opposition and confusion over whether local authorities should be able to opt out.
Secure Communities shares fingerprint information from local jails with the FBI and federal immigration agencies with the intent of identifying undocumented immigrants. A record 397,000 undocumented immigrants were deported in 2011, thanks in part to Secure Communities.
At Wednesday's hearing before a House of Representatives committee, Congresswoman Maxine Waters, D-California, said the program was not efficient and prone to make mistakes, especially about immigration status.
Addressing Gary Mead, the executive associate director of enforcement and removal operations for Immigration and Customs Enforcement (ICE), Waters asked why 93 percent of all people deported with the help of Secure Communities have been Latinos.
"It is not as a result of racial profiling or country of origin," Mead said. "We have enforcement programs that look for those persons that were here unlawfully and we apply the law equally to them."
Both Democrat and Republican lawmakers accused ICE of a lack of transparency when it comes to deportations and other immigration enforcement methods.
