"In April 2009, the Department of Homeland Security (DHS) issued new guidance on immigration-related worksite enforcement--the enforcement of prohibitions on the employment of unauthorized aliens in the United States. In the words of DHS, the updated guidance 'reflects a renewed Department-wide focus targeting criminal aliens and employers who cultivate illegal workplaces by breaking the country's laws and knowingly hiring illegal workers.' According to 2010 estimates, there are some 8.0 million unauthorized workers in the U.S. civilian workforce. Questions arise as to how rigorous and effective DHS's worksite enforcement efforts are and have been in past years. The department maintains data on several measures that can be used to examine the performance of its worksite enforcement program. Enforcement activity by the Department of Labor (DOL) is also relevant to a discussion of federal efforts to address unauthorized employment. DOL, which is responsible for enforcing minimum wage, overtime pay, and related requirements, focuses a significant percentage of its enforcement resources on low-wage industries that employ large numbers of immigrant--and presumably large numbers of unauthorized--workers."
CRS Report for Congress, R40002