D is a corporation that employs approximately 170,000 people in the United States. D provides labor for the Staples Center in downtown Los Angeles. D received letters from the SSA notifying it that the social security numbers of some 3,300 of its employees nationwide did not match those in the SSA's database. D asked its regional managers to confirm that the information it provided SSA matched the information provided by employees and, if so, to require corrective steps from the employees they supervised. On April 15 and 16, 2003, instructions were relayed to 48 D employees working at the Staples Center, to fix the issues or respond within 72 hours. If a new card or verification of renewal was required D must have it no later than close of business 4 pm on Wednesday, April 23rd, 2003. Failure to comply would mean termination. P requested an extension of time, and D denied this request. Fifteen employees obtained the requested documentation in time and continued to work. Thirty-three were fired. The employees were actually given seven to ten days to provide the required paperwork, though nothing in the record indicates that they knew they had this much time. The fired workers were told that they would be rehired if they supplied the required documentation; nothing indicates when they received this information. D did not know for sure why the terminated employees did not provide additional documents. Each of the fired employees had, at the time they were hired, properly completed the federal Employee Eligibility Verification Form (Form I-9) and provided D with facially valid documents establishing their identity and eligibility to work in the United States. P filed a grievance contending that D had fired them without just cause. The matter was submitted to binding arbitration. The arbitrator concluded that there was no 'convincing information' that any of the terminated workers were undocumented. The arbitrator found that the firings were without just cause, ruled in favor of P, and awarded the workers back pay and reinstatement. D filed a complaint in the U.S. District Court to vacate the arbitration award, and P counter-claimed to confirm it. The parties filed cross-motions for summary judgment. The court ruled in favor of D. The court reasoned that because the fired employees failed to indicate that they were beginning the process of correcting the SSN mismatch, D had constructive notice that they were ineligible to work in the United States. The court held that the arbitrator's award of reinstatement and back-pay violated public policy because it would require D to violate the immigration laws. P appealed.