Over 1,000 Immigration and Customs Enforcement agents on December 12, 2006 raided six Swift & Company beef and pork processing plants that employed a total of 15,000 workers, 7,000 on the first shift and 8,000 on the second (only first-shift workers were apprehended). Some 1,282 unauthorized workers were arrested, including 170 who were accused of identity theft; they used valid Social Security numbers belonging to other people to get jobs.

ICE said the Swift raid was the largest workplace raid ever conducted by immigration authorities; ICE director Julie Meyers said: "The action should send a clear message to employers: Hiring illegal workers is not acceptable." As ICE buses with unauthorized workers attempted to leave the Swift plant in Greeley, Colorado, some people tried to block them, and they left via another gate.

Under Operation Vanguard in 1998-99, the INS subpoenaed employee data from 40 meatpacking plants and checked it against databases, visiting plants to interview only those workers whose legal status was in doubt. Most of these workers quit before investigators arrived. Swift had employee records at Marshalltown, Iowa subpoenaed by ICE in March 2006, and advised some of the workers that their data were suspect; up to 400 quit before ICE arrived [Swift said that it re-examined workers with recently issued ID cards and Social Security cards who claimed to be citizens but had little or no work, education or residence history].

Both Swift and the United Food and Commercial Workers International Union, which represents workers at five of the six plants, denounced the raids. Swift has participated in the Basic Pilot employee verification system since 1997, but it cannot flag multiple uses of valid SSNs. Swift said that up to 40 percent of its workers may have used false SSNs to get hired, and that it paid a $200,000 fine in 2002 when Latino job applicants in Worthington, Minnesota were asked to provide additional proof of their legal status. This Swift fine was the largest employment discrimination case based on immigration status in history.

Basic Pilot is to be expanded from the current 12,000 employers who voluntarily participate to all eight million US employers within 18 months under the Senate immigration reform bill approved in May 2006.

After the Swift raids, the UFCW said that "Worksite raids are not an effective form of immigration reform. They terrorize workers and destroy families." The UFCW said that ICE should have interviewed only the 170 workers it sought for identity theft, not all 10,000 workers. Homeland Security Secretary Michael Chertoff warned that there would be more raids, saying "Obviously, when, even unwittingly, a business is significantly built on illegal labor, once we enforce the law, that's going to have a ripple effect."

Most economists expected little impact on pork prices, noting that hog slaughter is typically large through the fourth quarter, and then declines in the first quarter of the year. There may be more impact on beef prices, since there are a record number of cattle on feed for the winter months. Swift, the third largest US meatpacker after Tyson Foods and Cargill Inc, had sales of $9.4 billion in 2005.

Golden State Fence Company of Riverside, which currently employs 750 people, helped to build the border fence in San Diego. In December 2006, the company and its managers agreed to pay $5 million in fines for hiring unauthorized workers between January 1999 and November 2005.

Immigration and Customs Enforcement made 716 criminal worksite enforcement arrests in 2006, up from 24 in 1999 and 25 in 2002. The Southern Poverty Law Center filed a class-action suit in November 2006 against ICE for detaining legal immigrants in a September 2006 raid on the Crider Corp. poultry plant in Stillmore, Georgia, which led to 125 arrests.

Mis-matches. ICE in July 2006 proposed that employers give workers who generate SSA mis-match letters 60 days to correct their records. The Equal Employment Opportunity Commission said that the result could be more discrimination. ICE wants to change the law so that the Social Security Administration could notify it when SSNs are used multiple times to ease detection of unauthorized workers.

Some employers are firing workers who generate mis-match letters from SSA. Cintas Corp, which employs 32,000 US workers and is the target of union organizers, in Fall 2006 began to require workers to resolve SSN mis-matches within 63 days or be placed on unpaid leave.

On November 16, 2006 about 400 employees walked out of a Smithfield Packing plant in Tar Heel, North Carolina after dozens of workers were fired after failing to clear up discrepancies between the Social Security numbers they presented when hired and SSA records. The 5,000 employees, half Hispanic, process about 32,000 pigs a day. The United Food and Commercial Workers said it was not involved in the spontaneous walk out; Smithfield accused the UFCW of organizing the walk out, and said it risks fines if it ignores "on-match" letters. After intervention by local church leaders, Smithfield allowed some of those fired to return, but gave them a new deadline for clearing up the discrepancies.

Robert Block, "Swift, Hiring on a Knife's Edge," Wall Street Journal, December 20, 2006. Spencer S. Hsu, "ICE Sweep Was Largest Ever Against One Firm," Washington Post, December 14, 2006.