Exactly how did you know which ones were from illegal aliens?
They were the one claiming the phoney refunds, going to hispanic surnames at the same PO Box. Usually the illegal filed an early tax return using the SSN of a valid US citizen (usually hispanic as well), claiming a big refund. The scam was discovered when the second guy who really owned the SSN filed his return and the computer kicked it out as a duplicate. The second filer was legit, and didn't know the first fraudulent filer. Most of the time it was the tax preparer selling the SSN to the promoters who sold them to the illegals. Everyone but the tax preparer and the promoter were the victims in this scam.