There is a great article on John Bell's blog - The Digital Influence Mapping Project: "Don't over-react to a social media crisis"
Hugh McLeod sums up how organizations often take wrong steps in Social Media. It is not Advertising - it is a conversation.
Social media is a conversation
In my experience the detractors want to be heard and if a brand is really listening and not just using Social Media as a broadcast many situations that are initially perceived as a Social Media Crisis will quickly calm down and dissipate in to a largely forgotten timeline.The key is IF the organization demonstrates that it is really listening. When the naysayers think you are a faceless bureaucracy they shout louder. When they realize that there is a real person listening they will typically moderate their tone because they perceive that they are being heard.
So as John Bell's article points out. Stay calm. Take a deep breath. Show the community that you are listening. That you are human. That you really are authentic. Don't be afraid of admitting a mistake or misstep. Demonstrate that you are willing to learn from your community. It is these steps that will help to not only address a crisis but in many cases convert detractors in to supporters.
I witnessed a small case like this last week. Google made a change to their bookmark gadget on iGoogle. It was a usability disaster. It looked pretty but was less than usable. Users hit the comments board for the widget and panned Google. A string of 1 star reviews. Within hours the widget had been reverted to it's original design. The comments board lit up again. This time with overwhelmingly positive responses. Those detractors had been converted to supporters. Google had listened.