In the event that an employee says something bad about an employer's product, it would seem logical that the employer could take action. However, the type of action and when that action could be taken has been limited by several court decisions. In a March 2016 case, the U.S. Court of Appeals for the 8th Circuit ruled in that two employees of a Jimmy John's franchisee could not be fired for implying that the company's sandwiches were possibly being made by sick employees.
The employees were terminated by the franchisee after posting signs outside of the stores and on bulletin boards. In its ruling, the 8th Circuit said that the signs were not malicious enough considering Jimmy John's strict call off policy. Generally, employees are not allowed to call off due to illness unless they have a replacement. The ruling was based on several NLRB cases that said statements made during labor disputes were protected speech.
As a general rule, statements that have some elements of truth to them are generally protected even if there is no labor dispute per se. Furthermore, statements made about working conditions are more likely to be upheld as protected speech as opposed to statements about the quality of a product. Employers are asked to consider whether speech may be protected before taking action against employees who make disparaging comments about the company.
Employee rights can be both supplied by federal or state law or by legal precedent. People who feel that they have been unfairly treated when they attempt to exercise them, such as through termination or denial of a raise, may want to discuss their situation with an attorney in order to see what remedies they may have.