Ask HN: Good, balanced, fair policies on use of social networks?

Folks, I'm looking for examples of good company policies on the use of social networks. Notice the judgement-laden word, "good": I'm hoping for policies that much of the HN crowd would respect, policies that respect the line between work life and personal life, between being asked to do things in accordance with one's principles and preferences and being directed to do things that may violate those principles and preferences, etc.

We'd like our employees to promote us, at least by keeping their LinkedIn, et al, accounts up to date - and that might be about it. We also want clear principles and guidelines that our HR and admin staff can follow when doing their work, so that they don't step over the line in an enthusiastic and well-meant moment - and we don't want detailed rules, because those constrain rather than inform.

Sure, sure, I could spend some crafting just the right words, but being of the "lazy developer school", I'd rather stand on the shoulders of giants, as it were: If your company has a social networks policy or statement of principles or code of conduct, etc., that you like and respect, and that you can share, please do.

If this isn't clear, please do let me know. Also, please note that I'm not looking for a lawyer, we have a good one, but lawyers help you do legally that which you've already decided to do (good ones, anyway :->). Once we have something close to what we think we want, we'll run it past the legal folks, but we're not starting there.

Thanks!