Is that they are an ideal vehicle to fuel dissension. During the former cold war, one of the things that the CIA liked to do was to smuggle photocopy machines into the disident groups behind the Iron Curtain as a sort of DIY kit to create thought crimes. (Both football fanzines and the punk movement did a similar thing in the late 1970s and 1980s).
Organisations like Sun and Microsoft are both using blogs to reach out the hearts and minds of influencers and other stakeholders. Unfortunately the power of blogs can also amplify voices of dissent.
Using a service like Blogspot and having a privacy protecting software service like Tor, allows you to create a virtual ID with no traceability; providing you with a Dooce-resistant way of corporate dissension in a responsible manner.
They allow individuals or group to wage assymmetric information warfare campaigns against larger corporate organisations and their countermeasures such as slick corporate communications teams. Take MiniMicrosoft for instance. (Kudos to Charles Arthur for the link). Picture courtesy of SterlingArtz.