The Emerging Media Coordinator at the Defense Information School, Staff Sgt. Joshua Salmons, was recently interviewed at SmartBlogs.  I found this especially interesting and relevant to all of us:

Social media has some of the same vulnerabilities, sure, but there are tools to mitigate risk just like with e-mail, computer use or the chance that a spouse will give away information on the phone. Short of locking up all employees in the basement, there will always be security risks. Social media does have its own set of vulnerabilities, but to write it off as a lost cause because of the risk is overreacting, in my opinion.

A very interesting perspective on social media in the military.  He responds to many of the criticisms of social media, a must read.