Google announced Buzz today, as we anticipated this morning. CNET has a workmanlike description of the social-networking service, which is integrated into gmail. CNET identifies a central obstacle Buzz will have to overcome to gain traction: "The problem, however, will be the increasing backlash Google is seeing from the general public over how much data the company already controls on their online habits." Buzz is being rolled out over the next few days so some people will see a Buzz folder in their gmail, but most won't yet (this Twitter post explains how Safari users can get an early glimpse). A blog posting up at O'Reilly Answers points out some of the distinguishing characteristics of Google Buzz — one interesting one being its ability to post an update either publicly or privately, at the user's option. This design choice places it between the public-by-default Twitter and the private-by-default Facebook. Lauren Weinstein sounds a note of caution about the inherent privacy risks of Google's method of filling out initial friend profiles by automatic friending.