Once again contradicting the myth that illegal immigrants are simply desperate hard-working people in search of a better life, about 700 have been arrested at an Iowa meatpacking plant for stealing the identities and Social Security numbers of unsuspecting Americans.

Armed with a criminal search warrant, around 100 federal agents raided the nation’s largest kosher meatpacking plant, Agriprocessing Co., located in the northeast Iowa community of Postville. The plant is the area’s largest employer with about 1,000 workers, the majority of them believed to be in the country illegally.

Homeland Security agents from Immigration and Customs Enforcement say they were searching for evidence relating to aggravated identity theft, fraudulent use of Social Security numbers and other crimes. The magnitude of the operation is so large that last week the government leased a large Waterloo fairground site to process and perhaps detain the illegal aliens.

Rather than present fake documents to work, illegal immigrants are increasingly participating in criminal rings that steal the legitimate identities of American citizens. The problem is rampant nationwide and thousands have been arrested in the last few years.

In less than a year two separate operations in different parts of the country have led to the arrest of hundreds of illegal immigrants for using stolen identities to work. In one case, the illegal aliens used dead, juvenile and elderly Americans’ Social Security numbers to work at an Oregon food processing plant operated by food giant Del Monte.

In another case, more than 100 were arrested for using the stolen identities of legal residents to work a big poultry plant in a rural Missouri town. The illegal immigrants—from Mexico, Guatemala, Honduras and El Salvador—used “legitimate” drivers licenses and Social Security numbers purchased fraudulently from a dealer.

These incidents undoubtedly shatter the favorable portrait, long presented by immigration advocates, of honest and hard-working illegal immigrants who simply want to feed their families and pursue the American dream.