Generally what I've found is that there are a few people wholeheartedly for social media in government (I'd call them visionaries) and then the vast majority who want to "run the other way." The nay sayers only see the risks involved with the new way of communicating with one another and more importantly with the general public, a two way communication at that!
I recommend reading this Government Technology Magazine article Study: 8 Essential Elements for an Effective Government Social Media Policy Generally it calls out all the issues that might be encountered in trying to implement a social media policy. It will give you plenty of ammunition if what your goal includes is shooting the concept down.
You can download the entire guide as a pdf from the Center for Technology in Government.
