PR people working for large organisations should refer to the ClueTrain Manifesto for guidance when wondering how best to respond to comments about them on blogs or social networks.

The Cluetrain Manifesto points out:

Markets are conversations

Markets consist of human beings, not demographic sectors

Conversations among human beings sound human. They are conducted in a human voice

Whether delivering information, opinions, perspectives, dissenting arguments or humorous asides, the human voice is typically open, natural, uncontrived

The internet is enabling converations among human beings that were simply not possible in the era of mass media

In all interactions, speak with a human voice, and be honest when admitting your mistakes. And remember, as Jeff Jarvis points out in his book What Would Google Do?, that everything you say is searchable.