The term "supervisor" means any individual having authority, in the interest of the employer, to: hire, transfer, suspend, lay off, recall, promote, discharge, assign, reward, or discipline other employees, or responsibility to direct them, or to adjust their grievances, or effectively to recommend such action  A worker who has the authority to do these acts must do so with independent judgment, and not because it is of a merely routine or clerical nature. 29 U.S.C. 152(11). The NLRB has stated that responsibility to direct means the individual must be accountable for the performance of the task by the other [employee], for example, suffering a negative consequence from the employer when the tasks were not adequately performed by the other employee. Even if an employee is excluded as a supervisor from the right to engage in concerted protected activity, they are still protected from retaliation for participating in NLRB proceedings. For example, they cannot be fired for testifying about an unfair labor practice. In 2001, in a case known as Kentucky River , the Supreme Court criticized the NLRB for its formerly more narrow interpretation of the term "independent judgment," opening the door for the NLRB to expand the definition of who is considered a supervisor. In 2006, in a partisan 3-2 vote, the NLRB issued a ruling that expanded the scope of the "supervisor" exclusion. In Oakwood Healthcare, Inc., the NLRB said that permanent charge nurses in an acute care hospital, in assigning tasks to other employees, exercise supervisory authority, and therefore should be considered supervisors who are not eligible to be part of unions . According to the NLRB, independent judgment means at minimum [to] act, or effectively recommend action, free of the control of others and form an opinion or evaluation by discerning and comparing data. The individual must have a certain level of discretion that goes beyond a routine or clerical nature. Unions argue that the decision potentially takes away the federally protected right to form unions from 8 million nurses, building trades workers, newspaper and television employees and others.