Google as well as Yahoo, Microsoft and AOL among others are gearing up to keep a much closer eye on all of us, so that within five years these and other firms will routinely track our movements, friends, interests, purchases and correspondence - then make money by helping marketers take advantage of the information.

These companies' brash plans are pushing us toward a thorny choice that will determine the future of computing. Google and other Web-oriented, information-service giants are determined to build a breathtaking array of services based on your personal information, and they're betting you'll be willing to share it with them in order for you to reap the benefits. But if we cooperate and let them in on the details of our lives, we'll lose much of our privacy, and possibly a lot more.

A privacy backlash, however, would stifle these potentially revolutionary services before they get off the ground - and leave the computer industry's biggest plans for growth in tatters. That may be just what some people want. The U.S. Congress is considering four bills that would make it illegal to collect and share information online or through cell phones about people without clearer warning and permission. These sorts of restrictions are already in effect throughout much of Europe, thanks in part to European Union directives on privacy and electronic communications passed in 2002 and 2003.

The good news is that there's no reason to choose between technology and privacy. New technologies are emerging that can doctor our data so that companies know just enough about us to ply us with customized services, while preventing them from getting a clear picture of our private lives. The question is again one of trust: in this case, whether people will come to trust the companies that are trying to build these new technologies.

(abridged from Next Frontiers in Newsweek, April 3, 2006)