Employees (union and nonunion) who share information in an effort to improve their working conditions are protected under The National Labor Relations Act (NLRA). This is considered “protected concerted activity” because it is for the “purpose of negotiating the terms and conditions of their employment or other mutual aid or protection.” www.nlrb.gov.
Examples of protected concerted activity may include employees discussing their concerns about salary or working conditions or employees wearing political buttons or shirts referring to a topic protected by the NLRA, such as “X candidate favors improved healthcare.”
Again, to receive protection under the NLRA, your political speech or expression must relate to working conditions and must have some connection to group action or an attempt to bring a group complaint to the attention of management. www.nlrb.gov
Comments on social media that are “mere gripes not made in relation to group activity among employees” is not protected. Likewise, speech that is profane, defamatory or malicious against the company is not protected. NLRB v. Honda of America Manufacturing, Inc. An employer will also have a duty to act if the political speech infringes upon a protected group (based on their gender, race, age, disability etc.) and creates a hostile work environment for other employees.