I think Google should remove Buzz from GMail by default. Technically it probably makes no difference. Same privacy risks either way. The bigger issue is perception. I think most people approach GMail as a private space. They are very aware of the private data they keep in GMail. They've been using GMail for users under this assumption of privacy. All the sudden this public information exchange is one click away. If every bit of my information on Facebook was leaked I wouldn't be too upset because I've always approached it as a public space. I have an expectation that nothing on FaceBook is really private. I have an expectation everything in GMail is.