There is a bit of concern that Google's new Gmail-based social-networking tool, Buzz may tell complete strangers all your secrets.

A feature that compiles a list of the Gmail contacts who users most frequently e-mail or chat with and Buzz automatically starts following them It also makes the list public, meaning strangers can see who Buzz users have been in contact with. As Silicon Alley Insider pointed out a wife could discover that her husband emails and chats with an old girlfriend or a boss could discover a subordinate emails executives at a competitor.

Of course it is not quite as bad as that. Buzz only shares information about other people who are using Buzz and have set up public profiles in Google. So currently, most Gmail users are not publicly listed by the service. Users can also "unfollow" people who they don't want to be linked to. Buzz requires users to set up a public profile before they can post messages, it does give them an option to hide who they are following and who is following them.

However, the default setting is to make the information public, and only users who click on an "edit" tab can see the choice to opt out.  So people might start using Buzz may be publicly linked to other users without knowing.