Consignment sale operator Rhea Lana Riner has sued the U.S. Department of Labor for hurting her business. Riner uses volunteers to staff her consignment sales. In return, the volunteers, mostly retirees and stay-at-home moms, get the chance to shop early at the sales. But the Labor Department says Riner is violating federal law by not paying the volunteers minimum wage. It told those volunteers they can sue for back wages. None have done so, but Riner contends the threat of lawsuits has harmed her business.