The U.S. Chamber of Commerce just released a Survey of Social Media Issues Before the National Labor Relations Board (report available here and reported on here). The report summarizes of NLRB actions involving social media and related issues. According to the Chambers review of more than 129 cases: 

The issues most commonly raised . . . allege that an employer has overbroad policies restricting employee use of social media or that an employer unlawfully discharged or disciplined one or more employees over contents of social media posts.

Technology provides employees and unions with tools that can be simpler and more effective than one-on-one conversations or picket lines. Employees and unions use of social media can also be disruptive to the workplace and damaging to the employers reputation.

The summaries in the U.S. Chamber of Commerce report provide instructive guidance for employers seeking to craft policies or respond to employees or unions utilizing social media.

Of particular interest is this reports finding that a significant percentage of the cases surveyed involved non-union employers with no previous history of union involvement. This area of law is bound to continue to evolve as the NLRB seeks to apply legislation crafted in the Great Depression to the brave new workplace.