This really gets to the core issue of conduct on the Social Web. My simple answer? Don't manage it. At all.
Sure, there are some obvious caveats: hate, indecency and language, porn, bullying. Filters and moderation policies can and should catch a lot of this. But generally this question is more about "What if someone says something we disagree with as a brand?" Well, too bad. That is life on the Social Web. The thing to realize is that these conversations are occurring all the time, whether you entertain them or not. It seems better to me to at least participate and respond than to simply ignore them or pretend they don't exist.
When someone posts something negative, you've got three choices:
1. Ignore it. Sometime this is OK, but in general some sort of response simply to show the rest of the community that you disagree is in order. Very often, your own evangelists will take care of this for you.
2. Learn from it. If someone says your product is too expensive...hey, maybe it is! In that case, either make the value proposition more clear, or, do something to bring the price in line with what your customers are willing to pay.
3. Engage. Use this sparingly, especially if it's within your own community. You don't want to dampen conversation. But, if someone does say something outrageous...there is no reason why you should not provide an alternate point of view.
