Many of the holdouts mention concerns about privacy. Those who study
social networking say this issue boils down to trust. Amanda Lenhart,
who directs research on teenagers, children and families at the Pew
Internet and American Life Project, said that people who use Facebook
tend to have "a general sense of trust in others and trust in
institutions." She added: "Some people make the decision not to use it
because they are afraid of what might happen."