The world’s delivery giant, United Parcel Service, has been receiving some unwanted packages these days from the federal government: lawsuits.

Late Thursday, in what the Equal Employment Opportunity Commission is calling a “major class lawsuit,” UPS was sued in federal court in Chicago for allegedly denying sufficient medical leave to disabled employees. The Thursday suit claims UPS sets arbitrary deadlines for returning to work after medical treatment — in one case firing an employee who would have exceeded its 12-month leave policy by mere weeks — in violation of federal law.