Can Employers Restrict Behavior?

I listen to NPRs Talk of the Nation podcasts, and in looking back listened to a segment entitled "How Much Can Employers Limit Worker's Behavior?"

This was just after Keither Olberman returned to the air after being suspended for making three donations to Democrats, which violated NBCs ethics policy. For more info read: http://www.cbsnews.com/8301-503544_162-20021940-503544.html

The controversy raised some important questions, which the NPR Podcast examined.  Read the transcript, or listen to the podcast here: http://www.npr.org/2010/11/11/131247655/how-much-can-employers-limit-workers-behavior

This is a Human Resource concern, to which I hope our HR professionals respond to, as well as a Politcal and Symbolic matter.  Large questions of Communication and Ethics also arise....

What rights do we have as employees for self expression?  When is it fair to restrict or limit an individual POV?

Framing this issue againts a case where a women spoke very negatively about her boss on Facebook, to which some of her colleagues commented on her posting.  She was fired, and then the National Labor Realtions Board said the company was wrong to fire her because it was "protected speech" - basically that it amounted to "water cooler talk", and employees have a right to gather together and to discuss their workplace - e.g. unionization (informal and formal).  In another example a man was fired for burning a Koran, but would that have been protected under free speech?  Within this there are very gray areas indeed!  What do you all think about the differences between private and public sectors.  In the private sector employees are obliged to keep "trade secrets" whereas the expectation of the public sector is transparancy.

What struck me most about the podcast was the discussion on "at will" employment.  At will means that either the employeer or employee can end employment without a reason, unless of course illegal activity or discrimination is involved.  As I listened to the arguments I arrived at an important conclusion, even if you think you are protected by your speech or display for any reason - "at will" (really any) employees should still proceed with caution.  Mr. Steven Greenhouse, from the NY Times, says in this podcast that he likes to think about how an employer can fire someone "because it doesn't like the color of your shoelaces." The point I that I heard was to always be cautious because if an employer wants to get rid of you, they will find a way, regardless of the law.  So for me, professional decorum should be observed at all times.  Of course this is simplified, and there are certainly situations that warrant speaking up againts bad bosses, bad companies, or bad situtations, but ensure you are justified in doing so, and always proceed with caution.
-Ken