I just read (thanks, @MollyDiBi) about an attorney in Indiana who was fired for tweeting his views on how pro-labor protesters in Wisconsin should be handled. Perhaps an employee management course is in order for him? But I digress.
I read about this shortly after giving a presentation to a client's workforce about social networking, the workplace, and the blurry line that defines who they are professionally from who they are personally.
And that's our trade-off for participating in, and allowing employees to participate in, the social media web. I'm fine with that exchange since I understand my firm's policy on taking stands and sharing views. Are your employees familiar with your policy? If you aren't sure, it's best to over-educate than to learn the hard way that someone thought her innocuous post about the Communism-inspired traffic light cameras actually stirred up a little trouble in the community.