The IRS is now the focus of a year-long audit, thanks to federal employees who are blowing the whistle. Howard Antelis is a tax examiner at the IRS's ITIN processing center in Austin, Texas. The large, unmarked building in south Austin is where the IRS decides whether to issue an Individual Taxpayer Identification Number to the millions of illegal immigrants who apply for them. An ITIN allows undocumented workers to file tax returns and pay taxes, a legal requirement for those who earn income in the United States … even those who come to the country illegally. But 13 Investigates...