Social media: the digital water cooler. And what your employees say about you or your company online may be protected speech, as has been shown in some of the headline-making cases that follow.

One now-famous case between employee and employer resulted in a lawsuit against American Medical Response of Connecticut, brought by the National Labor Relations Board. The suit claimed AMR employee Dawnmarie Souza, an ambulance driver and Teamster, was unjustly fired and denied union representation after she allegedly mocked her supervisor using obscenities on her Facebook page. She purportedly called her supervisor a "d–k" in one post and "a scumbag" in another, though the actual postings were not made public.

Souza won the case, with the NLRB ruling that the termination violated the National Labor Relations Act, which allows employees to discuss the terms and conditions of their employment with co-workers and others.