A new Department of Labor rule enacted this month requires companies to disclose use of union-busting firms hired to dissuade their employees from forming unions. Labor has praised the rule as a step toward balancing the playing field — union busting has grown from a small industry in the 1970s to a multibillion dollar international industry intent on robbing people of their voices at work.

The new rule closes a loophole in a previous that excluded union busters who did not have “direct” contact with employees. Find out more here.