The Minnesota Court of Appeals recently reversed the conviction for identity theft and forgery of Iris Janeth Maldonado-Arr-eaga, who was rounded up along with 48 others as part of an immigration raid in Willmar, Minnesota in April 2007.
The conviction was reversed because the prosecution introduced into evidence biological information that should have been suppressed pursuant to the U.S. Constitution. Other convictions from the same raid (and maybe others) should also have been reversed but the illegal immigrants were deported long before they could perfect an appeal.
I know from my experience investigating personal injury cases (particularly involving injured farm workers) that the use of stolen and/or purchased Social Security numbers is rampant among illegal immigrants. They apparently do not give it a second thought. That is why there are so many identity theft convictions that come out of INS raids, such as the one in Mississippi last year.