If the information is corrected, the earnings are reported back to the owner's file, says Clark. If not, it remains indefinitely in the suspense file, which has been around since 1937, she says.

While theft by undocumented workers is now perhaps the most visible type of identity theft, getting a job is only one of many motivations for it, says Utah U.S. Attorney Brett Tolman. Tolman's office prosecuted at least 50 identity-theft cases involving 80 defendants from August 2006 to August 2007, and the most common type of case involved bank fraud.

"It is a crime that is rampant," says Tolman. "If you were to survey law enforcement, state and federal, they would indicate that it's a very top priority."

Often, identity theft is tied to drug use or greed, Tolman says. Or it can be rooted in other crimes. He points to Kirk Alan Swearington, who was convicted of child-pornography possession earlier this year, after he attempted to rent an apartment with a false name and a Social Security number that belonged to a 91-year-old man.

There's no record of exactly how many undocumented immigrants have purchased a Social Security number to work. But Hamp says illegal immigration is now responsible for more than 90 percent of the cases that he sees.

"The volume of it is new," Hamp says, adding that the trend dates back to a 1986 federal immigration reform, which mandated that employers keep on record the I-9 employment verification form that includes information such as name and Social Security number.

Hamp says identity theft is victimizing an increasing number of children. The state attorney general's Protect the Children campaign arose when a few victims in a mortgage-fraud investigation turned out to be children. In the first quarter of 2005, the Department of Workforce Services' database showed about 3,500 children 12 and under who appeared to have had their identity stolen.

At a recent interim meeting of the Legislature's Business and Labor Committee, lawmakers expressed frustration at the federal government's inaction on immigration issues, including identity theft.

After that meeting, the Bush administration announced a new policy which had been scheduled to take effect this month, however a U.S. district court issued a temporary restraining order against implementing the policy while it is under litigation. The policy gives employers a specific time line to clear up mismatches between names and Social Security numbers — or else fire employees.

The Utah legislative committee formed a working group to look at whether to require that businesses use a recently revamped federal Internet-based verification program, now called E-Verify.