From this:

...a lawsuit filed against the Department of Homeland Security this week contends that the new rules are discriminatory and will lead to mass firings of legal workers. Even United States citizens will face discrimination if they look or sound foreign, according to the suit.

Filed in a San Francisco federal court this week, the 17-page complaint [link] also names the Social Security Administration as a defendant because it says letters informing businesses of discrepancies between employee records and the agency's database would violate worker’s rights and impose burdensome obligations on employers.

And, from this:

But leaders of the U.S. Chamber of Commerce and a coalition of trade groups representing the politically influential construction, lodging, farming, meatpacking, restaurant, retail and service industries appealed on Monday to the Department of Homeland Security and the Social Security Administration to postpone the plan's implementation for six months.

Raising the possibility of plant closings, autumn-harvest interruptions and other destabilizing consequences for the U.S. economy, 50 business organization members of the Essential Worker Immigration Coalition signed a letter warning of "uncertainties, disruptions, and dislocations throughout broad swaths of the workforce," as well as discrimination against Hispanic and immigrant workers.

DHS spokeshole Russ Knocke says they'll fight the lawsuit "vigorously", something I tend to doubt since Chertoff and Bush are on the same side as EWIC, the ACLU, and the AFL-CIO in supporting illegal immigration.