Illegal immigrants are not eligible for social security benefits or the earned income tax credit. Since 1996, however, they can get a special Immigrant Tax Identification Number

(ITIN) that enables them to pay federal taxes without a social security number. In 2006 the IRS issued some 1.5 million ITINS, the most ever, and news outlets reported that spring 2007 saw an increase in federal tax filings from undocumented aliens. What are the pros and cons of this approach?