HARTFORD, Conn.—Terms of the settlement of the case of an employee who was fired for posting negative comments about her supervisor on Facebook sends a warning to employers that their social media policies should not be overly broad, legal experts say.

On the eve of a scheduled hearing by the Labor Relations Board's Hartford, Conn., regional office against American Medical Response of Connecticut Inc., AMR settled the complaint last week by agreeing to revise its blogging and Internet policy to ensure that it does not improperly restrict employees from discussing their wages, hours and working conditions with co-workers and others outside of work.

The complaint filed in October was the first time that the NLRB addressed social media and its impact on the workplace.

Though an agreement was worked out between Dawnmarie Souza, a union worker for AMR's New Haven, Conn., office, who was fired in December 2009 after disagreements between her and her supervisor culminated in Ms. Souza posting negative remarks about the supervisor on Ms. Souza's personal Facebook page, the NLRB's complaint shows it is taking a new approach to how employers enforce social media policies, labor and employment attorneys say.

“Though there was no decision in this case, I think employers need to recognize that the NLRB-issued complaint shows a change,” said Seth Borden, New York-based partner in McKenna Long & Aldridge L.L.P.'s labor practice. “Three or four years ago, it was very likely the board would not have filed this complaint, and it shows a marked change in direction in how it views social media,” he said.

In the settlement, AMR said it would neither discipline nor discharge employees for engaging in discussions pertaining to wages, hours and working conditions in online forums. The medical transportation company also agreed that future employee requests for union representation will not be denied and that employees will not be threatened with discipline for requesting union representation, according to the settlement.

Allegations involving Ms. Souza's termination were resolved through a separate, private agreement between the employee and the company, the NLRB said in a statement.

A request for comment from Glenwood, Colo.-based AMR was not returned.

The NLRB's regional office had alleged that the company illegally denied union representation to Ms. Souza during an investigatory interview, and maintained and enforced an “overly broad” blogging and Internet posting policy that resulted in her firing.

Under the National Labor Relations Act, employees may discuss terms and conditions of their employment with co-workers and others, regardless of the forum.

After the interview, Ms. Souza posted a negative remark about her supervisor on Ms. Souza's personal Facebook page from her home computer. The post drew supportive responses from co-workers and led to more negative comments by Ms. Souza about her supervisor, including calling her “a number 17,” AMR's term for a psychiatric patient, according to the complaint.

The NLRB regional office found that Ms. Souza's Facebook postings were a “protected concerted activity,” and that AMR's blogging and Internet posting policy contained “unlawful provisions, including one that prohibited employees from making disparaging remarks when discussing the company” and another that “prohibited employees from depicting the company in any way over the Internet without company permission.”

Sara A. Begley, a Philadelphia-based partner and attorney who focuses on employment law with Reed Smith L.L.P., said that while the settlement doesn't set a precedent, employers should review their electronic usage and social network policies to make sure the language is not so restrictive as to impinge on protected “concerted activity” by employees.

“The message from the settlement is that Facebook postings may be deemed to be "concerted activity,' especially where an employee is commenting about working conditions, the conduct of supervisors, etc., and other employees are responding or posting their own comments,” Ms. Begley said.

“Any adverse employment action taken against an employee with respect to the same may subject the employer to a complaint by the NLRB or a lawsuit by the employee themselves,” she said. “The issue is not necessarily about the mode of communication, but rather the substance and the intended audience.”

However, she said not all Facebook “rants” will be protected, noting that malicious conduct such as racist or sexist comments that are tied to the workplace, anti-competitive or disparaging remarks about competitors, disclosure of trade secrets or proprietary information, and defamatory or slanderous comments about co-workers or managers will not be protected.

“There still seems to be a gray area between defamation and disparagement of an employer; and until the NLRB decides that, I think employers should be careful in how they enforce their social media policies,” said Eric B. Meyer, Philadelphia-based employment law attorney and associate with Dilworth Paxon L.L.P.