You’ve probably seen them. Large, inflatable rat balloons, usually with sharp, pointy teeth, show up periodically at workplaces when a union is protesting the labor practices of a non-union contractor performing work for a hospital, business, or other organization.

 Non-union and business groups say the rats are coercive, and therefore not protected under the National Labor Relations Act. Unions argue that they are exercising their free-speech rights by highlighting labor practices they don’t agree with.

 The National Labor Relations Board seems to be inclined to agree with the unions. In a May 25 decision, the nation’s top labor panel upheld the right of unions to display large, inflatable rats at the workplaces of secondary employers—employers who have hired a non-union contractor to build or retrofit a building or other construction project.

The board was divided in its ruling, with Chairman Wilma Liebman, and members Craig Becker and Mark Pearce concluding that the use of rats on a secondary employer’s workplace is not coercive: the unions involved in the protest at an acute care hospital did not shout, prevent access or otherwise interfere with the hospital’s operations.

 In his dissent, Member Brian Hayes, a Republican, said that the rats are indeed coercive and therefore should be unlawful. “For pedestrians or occupants of cars passing in the shadow of the rat balloon, which proclaims the presence of a ‘rat employer’ and is surrounded by union agents, the message is unmistakably confrontational and coercive.”

 The majority said it relied on the reasoning it used in a 2010 decision Carpenters Local 15006 (Eliason & Knuth of Arizona, Inc.), which ruled that the display of large, stationary banners at a secondary employer’s workplace was not unlawful.

 What do you think? Should this type of demonstration be out of bounds, or is it protected free speech?