The Plaintiffs allege that Google automatically enrolled Gmail users in Buzz, and that Buzz publicly exposed data, including users’ most frequent Gmail contacts, without enough user consent.
Google has also made changes to Google Buzz that clarify its operation and users' options, including, in particular, changes regarding user information and control over Buzz's privacy settings.
everyone who has a gmail account got that mail. as it concerns any that might have been effected by the breach of privacy. standard covering of their own corporate backside to appease the courts.