"Undocumented employees, the court reasoned, are like at-will employees: the fact they do not have a right to continued employment does not excuse employers from following the employment laws. There is also an important policy consideration. If employers could skirt liability by hiring undocumented workers, then the Immigration and Nationality Act, which places restrictions on hiring undocumented workers, and the Wisconsin FMLA, which safeguards employees' rights to take medical leave, would be frustrated." [Burlington Graphic Systems, Inc. v. Dept. of Workforce Development, Appeal No. 2014AP762 (Wis. App. Dec. 23, 2014)]