WHOEVER THE vice presidential contenders may be, one thing is for sure: Their pastors, contributors, and fund-raisers are being checked out. So are their friends and their friends' friends. Senator John McCain is using Google, but there are better tools. And in the next campaign, the checking is going to be more automated, for better or worse.
That helps explain why Facebook, founded less than five years ago, may be worth $15 billion. The value of Facebook is not only in its software, its patents, and its smart people. Facebook has an enormous database of who knows whom, an electronic catalog of the interconnections and interests of its members. The daily updates of my friends' new friends and what groups they have joined are like tiny, atomized birth announcements, inviting me to contribute my own updates. And a single corporation holds all this information. Indeed, Facebook might be remembering whose friendship invitations I refused.
Facebook's vast social network would be invaluable for checking reputations. The same data can help sell stuff - though earlier this year, Facebook found that telling members what their friends had bought was going too far even for the always-connected generation. Other sites help make business connections - LinkedIn.com's motto is "Relationships matter," and jigsaw.com encourages everyone to submit others' contact information so clients can "bypass gatekeepers" and "go straight to decision-makers."
We can hope for common sense about information privacy, but technology keeps changing the norms. A few years ago, a public catalog of all the nation's swimming-pool owners would have been shocking, but today anyone can use Google Maps to look down into people's back yards. Our friendship circles are likewise going to be more public in the future.
Staying off Facebook won't keep your social Web private. There are many public sources from which social network information can be culled. This is high school graduation season - and the class lists are all online. Newspapers and blogs are online - and computers can connect people simply on the basis of whether they are mentioned in the same article. Go to fundrace.huffingtonpost.com to see a map of political contributions, with red and blue dots marking your neighbors' houses.
Technological convergences create creepier opportunities for cataloging who knows whom. Millions have contributed their family photos to online album sites such as Flickr. Polarrose.com can identify the faces of thousands of people. Put the two together and you could construct a vast network of who appears with whom in the same publicly posted photograph.
That would include the photo of you in Aruba, where you just happened to be in the background while I was snapping a picture of my family at the next table. All of a sudden you are part of my implied social network - complete with the date and location of your dinner.
Here we see things going wrong, but how to fix them? You should be able to go to Aruba without the whole world finding out, and I should be able to post my vacation snapshots without your permission.
All this information - from Facebook "friends" to neighboring diners - lacks context. Links established by computers may not be real social connections. Subtleties debated in the presidential campaign - are Barack Obama's relations to the Rev. Wright like McCain's to the John Rev. Hagee? - will probably be lost when linkages are collected by such driftnet fishing. Already, Facebook says that it supplements the information you provide about yourself with material you can't control, drawn from "newspapers, blogs, instant messaging services, and . . . photo tags."
Privacy is changing rapidly and in ways we can barely comprehend. Will we live our lives differently, fearing that our everyday social contacts are going to wind up in some great database? How will the world change when group photos snapped at parties all turn into misleading edges in that permanent, all-encompassing social graph? Can society limit the abuse of personal information without resorting to Internet censorship that would violate the First Amendment?
Harry Lewis is professor of computer science at Harvard and Fellow of the Berkman Center for Internet and Society. His new book with Hal Abelson and Ken Ledeen, "Blown to Bits: Your Life, Liberty, and Happiness After the Digital Explosion," has its own Facebook group.