In the June/July edition of the Louisiana Bar Journal, New Orleans attorney Michelle Craig relates some good advice for employers.  She discusses social media sites.  She advises employers to not routinely comment to employees about the contents of posts, blogs or comments.  She notes this could suggest the employer is conducting surveillance of its employees.  Surveillance is one of the actions prohibited by the National Labor Relations Act.  

The NLRA also prohibits reprisal against employees who discuss terms and conditions of employment. See my earlier post about this sort of reprisal.  Forbidding an employee from discussing terms and conditions of employment in any venue, including social media sites, would likely violate the NLRA.