You are an HR Manager in a large corporation in the U.S.  There has been some talk of unionizing your company.  What do your managers need to know?  Create a PowerPoint presentation to educate your managers.  Be sure to include any laws and governing bodies they need to be aware of and any dos and donts they need to keep in mind.  This presentation is just background.  Since this is only a response to rumors, you do not need to go into detail about the process of unionization yet, just give your management staff enough contextual information to keep your managers informed and your company out of legal trouble.