Giving Facebook password to employers

I just read an interesting article from Information Week about this controversy over giving your Facebook password to your employer.  Now I think that this partly is an invasion of ones civil liberties because you as an individual are entitled to free speech and this would be considered spying.  I am sure these companies are paranoid about being able to spy on their employees and must be able to see what they are saying about their company or who they may be talking to that works at one of their competitors.  For me it would be a bad thing to give out any password to your company because that is asking you for your personal information.  On the other hand it may be a security issue depending on who you work for.  It may be a policy in certain fields of the military to see if you are passing on any secure information to help avoid a situation like the wikileaks fiasco.  With that it may seem like the government wants to spy on you, but it may be necessary for security purposes.  I feel that this issue could go either way and each person will have to interpret it on their own.