Unsure of the correct usage of social media in your organisation, see what First Assistant Secretary John Sheridan has to say on the AGIMO Blog
Trust [your staff]: one person can’t engage with the social media universe on behalf of an organisation by themselves. We trust all manner of public servants to engage with the public every day, over counters and over the phone. We can trust them on social media too.
If only every agency or local government body realised this.