A settlement with the National Labor Relations Board in the high-profile “Facebook firing” case has turned conventional wisdom on corporate policies that govern employee use of the Internet and social media on its ear.

The language in those policies could now get employers in trouble with the NLRB. American Medical Response of Connecticut Inc. agreed to settle a complaint filed by the board’s Hartford office after it fired Dawnmarie Souza for posting negative comments about a supervisor on her personal Facebook page.