While speaking at a conference this year, I asked members of the Human Resources community to raise their hands if they routinely instructed employees not to discuss internal investigations. No surprise, most of the hands (maybe all of them) went up.
For many good reasons, most employers instruct employees to keep the fact of and contents of investigations confidential. For example, when investigations become public, employees often become less willing to come forward and discuss the nature of the investigation. Also, in most instances the nature of the investigation involves sensitive information, like a harassment complaint. Yet, the National Labor Relations Board (NLRB) has indicated that reasons such as these are not legally sufficient to tell employees to keep their mouths shut.