Privacy, whether we like it or not, has gone public. We are only just beginning to recognize how the Internet has redefined the relationship between our private lives and the public sphere. Every time we personalize a Web site, join a mailing list, or purchase a book or CD online, we open our lives to an ever-widening data network that offers us scant protection from the prying eyes of corporations, governments, insurance companies, or criminals. Has the e-commerce revolution permanently eroded all personal boundaries, or is it still possible to protect one's personal information in an...