The Fight for $15, which is funded by the Service Employees International Union, has challenged that entire premise. It argues that McDonald's really is the boss inside stores, exerting control over workers through the menu, the supplies and uniforms, the training materials, and even computer programs that determine labor costs. The franchise model, it says, merely helps the company shirk its duties to workers, by shifting legal liabilities onto franchisees when workers get shorted on pay or fired for union activism.