All IRS tax payer ID numbers (not to be confused with SS numbers) issued to illegals have the same format as regular SS numbers, but all start with the number "9" -- Apparently, the IRS is only interested in being paid taxes regardless of whether the employee is working illegally. BTW, it's true that employers are not allowed to ask their workers what their immigration status is, but the "9" ID number is a dead giveaway to the employer that his worker is illegal.
