In many contemporary legal contexts, the right to work refers to a right to work without being required to join a local union. As part of many collective bargaining agreements, unions will stipulate that all employees must join the union upon being hired. This requirement is seen as an essential means to pro¬tect the viability of the union by prohibiting "free riders," who reap the benefits of union membership without sharing the burdens. This also protects the entire collective bargaining system by preventing employers from hiring only those workers who promise not to join the union. Several states have passed legisla¬tion that prohibits such a requirement. This legislation is often referred to as a right-to-work law.