This response is provided for information only. You should obtain legal advice from your union’s attorney before taking action. Your question is very large in that there is an enormous body of law addressing this. No succinct answer will provide enough information for you to rely on.
The federal National Labor Relations Act, as amended, 29 U.S.C. §§ 151 - 169 (NLRA, also known as Labor Management Relations Act or LMRA) protects employees on strike in protest of a bona fide unfair labor practice (ULP). Generally, employees engaged in a ULP strike can say and do a variety of things inside the workplace, outside the workplace and close to the workplace.
Inside the workplace, ULP strikers can speak with one another about the working conditions and any efforts to organize or participate in the union. This may be true even if the communication causes some interference with work, particularly if the employer allows employees to talk about other non-work topics while on the job (movies, sports, recipes, auto repair, vacation, politics, music, Girl Scout cookies, etc.).
Usually, it is safe to distribute flyers or handbills in a non-work area (break room, parking lot, etc.) during non-work time. Both the workers passing out the flyers and the workers receiving the flyers must be off the clock.
Outside the workplace, employees can demonstrate, picket, pass out flyers or handbills, chant and sang, as long as they do not block access into or out of the workplace, are not disorderly or violent, and do not break other relevant laws.
Both inside and outside the workplace, ULP strikers can talk to the company’s clients or customers about the strike IF the employer lets employees talk to clients and customers about other non-work topics.
The subject of all the communications – whether on a picket sign, in a flyer or in conversation with someone doing business with the company – should be the unfair labor practice, not on how oppressive the company is. To best preserve the protected nature of the ULP strike, the strikers should restrict their messages to the topic of the strike and how the workers want the company to follow the law (stop committing unfair labor practices). If the communications are more general, such as protesting the employers overall treatment of employees or working conditions then the ULP-nature of the strike may be diluted and even lost.
The goal of the ULP strike should be to educate the public, not to harm the company by interfering with its business.
It is very important to preserve the unfair labor practice nature of the strike because, at the end of a ULP strike, the employer must allow the workers to come back to work. In a purely economic strike (that is, a strike for better wages or working conditions), the employer can replace the strikers.
twitter.com/MikaSpencer *** All legal actions have time limits, called statutes of limitation. If you miss the deadline for filing your claim, you will lose the opportunity to pursue your case. Please consult with an experienced employment attorney as soon as possible to better preserve your rights. *** Marilynn Mika Spencer provides information on Avvo as a service to the public, primarily when general information may be of assistance. Avvo is not an appropriate forum for an in-depth response or a detailed analysis. These comments are for information only and should not be considered legal advice. Legal advice must pertain to specific, detailed facts. No attorney-client relationship is created based on this information exchange. *** Marilynn Mika Spencer is licensed to practice law before all state and federal courts in California, and can appear before administrative agencies throughout the country. She is eligible to represent clients in other states on a pro hac vice basis. ***
Ms. Spencer's answer is quite correct. In Tennessee an employer can get a court order prohibiting picketers from blocking entrances or hassling people coming in or out of the premises.
I represent management only. Any answer here is a guideline. No attorney client relation is created. You should contact an attorney representing employees for legal advice.