As more and more employees take to social media to air their workplace grievances, one recent case shows that employers need to take a close look at the restrictions they place on employee “free speech.”

Earlier this month, the National Labor Relations Board reached a settlement with a Connecticut ambulance service in a case involving the termination of an employee who posted negative comments about her supervisor on her Facebook page. The case arose from a complaint issued by the NLRB claiming that her firing violated federal labor law because the employee was engaged in protected activity when she posted the comments about her supervisor and responded to other comments posted by her co-workers.

The complaint further claimed that the employer’s policies regarding internet posts, blogging and communications between co-workers was overly broad, and that the company had illegally denied union representation to the employee during an investigative interview.