Past HalloWeekends Screamsters

That's a bit odd saying a US passport will not do. The I-9 IRS forms still have no issue with a US Passport. In fact a valid US passport is supposed to be allowed by the IRS for employers to use just it alone without the 2 other forms of ID. (It establishes both citizenship and identity [official picture ID]. You had to provide the same other forms of ID and proof of citizenship [certified birth certificate] to get a passport issued to you.)

I know some employers though are just too lazy to read instructions the IRS has on it's forms though if it falls outside of what they were told/trained to do.

My guess is CP is using a photocopy of the SSN card as a cross-check to make sure they have the right SSN number and correct legal name.

The SS card is needed for the payroll department. It's been stated in several of the emails that have gone out if you've been hired.