When Google launched Buzz, a microblogging social network, several months ago, the company boasted that the network had been generated automatically, by algorithms that could connect users to each other based on communications revealed through Gmail and other services. However, many users balked at having what they perceived as mischaracterized social connections, forcing the company to frantically backpedal and make the Buzz service less automated and more under users' control. This incident notwithstanding, many companies are increasingly interested in automatically determining users' social ties through e-mail and social network communications. For example, IBM's Lotus division offers a product called Atlas that constructs social data from corporate communications, and Microsoft has investigated using such data to automatically prioritize the e-mails that workers receive. But researchers say there are a lot of unsolved problems with generating and analyzing social networks based on patterns of communication.