The Chicago Teachers Union and Illinois Federation of Teachers filed a lawsuit against Cook County Treasurer Maria Pappas over taxpayer funds. The Chicago Teachers Union and Illinois Federation of Teachers filed a lawsuit against Cook County Treasurer Maria Pappas over taxpayer funds. The Chicago Teachers Union and Illinois Federation of Teachers filed a lawsuit against Cook County Treasurer Maria Pappas over taxpayer funds. The Chicago Teachers Union and Illinois Federation of Teachers filed a lawsuit against Cook County Treasurer Maria Pappas over taxpayer funds. The Cook County treasurer's Office mails tax bills, collects payments and distributes funds to taxing bodies.