Shift Communications (the creators of the original social media press release template) have published a corporate social media policy template. I love open source approach that Shift have taken, generally the PR world are not great on sharing and growing on intellectual capital.
I’m not a fan of company policies but even I cannot deny the importance of this.
Here is the template courtesy of Shift communications: 
TOP 10 GUIDELINES FOR SOCIAL MEDIA PARTICIPATION AT (COMPANY)
These guidelines apply to (COMPANY) employees or contractors who create or contribute to blogs, wikis, social networks, virtual worlds, or any other kind of Social Media. Whether you log into Twitter, Yelp, Wikipedia, MySpace or Facebook pages, or comment on online media stories — these guidelines are for you.
While all (COMPANY) employees are welcome to participate in Social Media, we expect everyone who participates in online commentary to understand and to follow these simple but important guidelines. These rules might sound strict and contain a bit of legal-sounding jargon but please keep in mind that our overall goal is simple: to participate online in a respectful, relevant way that protects our reputation and of course follows the letter and spirit of the law.
1. Be transparent and state that you work at (COMPANY). Your honesty will be noted in the Social Media environment. If you are writing about (COMPANY) or a competitor, use your real name, identify that you work for (COMPANY), and be clear about your role. If you have a vested interest in what you are discussing, be the first to say so.
2. Never represent yourself or (COMPANY) in a false or misleading way. All statements must be true and not misleading; all claims must be substantiated.
3. Post meaningful, respectful comments — in other words, please, no spam and no remarks that are off-topic or offensive.
4. Use common sense and common courtesy: for example, it’s best to ask permission to publish or report on conversations that are meant to be private or internal to (COMPANY). Make sure your efforts to be transparent don’t violate (COMPANY)’s privacy, confidentiality, and legal guidelines for external commercial speech.
5. Stick to your area of expertise and do feel free to provide unique, individual perspectives on non-confidential activities at (COMPANY).
6. When disagreeing with others’ opinions, keep it appropriate and polite. If you find yourself in a situation online that looks as if it’s becoming antagonistic, do not get overly defensive and do not disengage from the conversation abruptly: feel free to ask the PR Director for advice and/or to disengage from the dialogue in a polite manner that reflects well on (COMPANY).
7. If you want to write about the competition, make sure you behave diplomatically, have the facts straight and that you have the appropriate permissions.
8. Please never comment on anything related to legal matters, litigation, or any parties (COMPANY) may be in litigation with.
9. Never participate in Social Media when the topic being discussed may be considered a crisis situation. Even anonymous comments may be traced back to your or (COMPANY)’s IP address. Refer all Social Media activity around crisis topics to PR and/or Legal Affairs Director.
10. Be smart about protecting yourself, your privacy, and (COMPANY)’s confidential information. What you publish is widely accessible and will be around for a long time, so consider the content carefully. Google has a long memory.
control the messages of your brand online. I couldn’t disagree more, we have never had control of what people say about your brands, we have always been attempting to influence them, but never been able to control them.
eek I had enough and 
.
