The National Labor Relations Board is investigating cases to determine if employers who wrongfully classify their employees as independent contractors prevents those workers from the right to organize. The Teamsters have also rallied around the cause through their recently filed complaint against an employer of port truck drivers who allegedly prohibited the employees from exercising their Section 7 rights. Major decisions are expected this summer from both the Columbia University and Miller & Anderson cases.
See "Is misclassification an unfair labor practice?", Brian Mahoney, Politico, April 21, 2016