"WASHINGTON -- Two federal agencies are refusing to turn over a mountain of evidence that investigators could use to indict the nation's burgeoning work force of illegal immigrants and the firms that employ them.

Last week, immigration authorities trumpeted the arrests of nearly 1,200 illegal workers in a massive sting on a single company, but they acknowledge that they relied on confidential informants and an unsolicited tip.

It didn't have to be that hard.

The Internal Revenue Service and the Social Security Administration routinely collect strong evidence of potential workplace crimes, including the names and addresses of millions of people who are using bogus Social Security numbers, their wage records and the identities of those who hire them.

But they keep those facts secret.

"If the government bothered to look, it could find abundant evidence of illegal aliens gaming our system and the unscrupulous employers who are aiding and abetting them," said Rep. J.D. Hayworth, R-Ariz.

The two agencies don't analyze their data to root out likely immigration fraud -- and law enforcement authorities can't do so because the agencies won't share their data.

Privacy laws prohibit that, they say.

The agencies also don't use the power that they have.

The IRS doesn't fine employers who repeatedly submit inaccurate data on workers. Social Security does virtually nothing to alert citizens whose Social Security numbers are being used by others.

Evidence abounds within their files, according to an analysis by Knight Ridder Newspapers and The Charlotte Observer.

One internal study found that a restaurant company had submitted 4,100 duplicate Social Security numbers for workers. Other firms submit inaccurate names or numbers for nearly all their employees. One child's Social Security number was used 742 times by workers in 42 states.

"That's the kind of evidence we want," says Paul Charlton, the U.S. attorney in Arizona. "If you see the same Social Security number a thousand times, it's kind of hard for them to argue they didn't know."

The potential crimes are so obvious that the failure to provide such information to investigators raises questions about Washington's determination to end the widespread hiring of illegal immigrants.

An estimated 7 million unauthorized workers are employed in the United States. They're picking crops, building homes and tending yards. In some cases, they work for the government on public projects that pay them with taxpayer money.

They've built roads in North Carolina and military housing in California and even helped rebuild the Pentagon after 9-11, until law enforcement found out.

They also work at airports, seaports and nuclear plants.

Homeland Security Secretary Michael Chertoff has asked Congress for access to earnings reports, sent by employers with money withheld for taxes and Social Security.

The reports contain workers' names and Social Security numbers, and when they don't match Social Security records, the information is set aside in what's called the Earnings Suspense File.

Created in 1937, the file contains about 255 million unmatched wage reports representing $520 billion paid to workers but not credited to their Social Security earnings records.

The incorrect worker files mushroomed during the 1990s as immigrants poured into the United States. Almost half the inaccurate reports come from industries such as agriculture, construction and restaurants.

"We believe the chief cause of [unmatched] wage items ... is unauthorized work by noncitizens," Social Security Inspector General Patrick O'Carroll told Congress in February.

The IRS also receives the mismatch information.

Particularly disturbing is that possibly millions of the Social Security numbers belong to other people.

In Utah, after Social Security provided data for one criminal inquiry, investigators discovered that the Social Security numbers of 2,000 children were being used by other people.

"What do you think we'd find if we had the ability to analyze all of their information?" said Kirk Torgensen, Utah's chief deputy attorney general. "It would be invaluable. How shortsighted is it that the government doesn't follow this trail?"  "

http://www.dfw.com/mld/dfw/news/nation/14411281.htm