I promised myself that I wouldn't post anything personal on Facebook, but it's tough to be resolute. The social network is an insidious blend of peer pressure and crowd psychology—watching all your "friends" on the site post every little detail of their lives, you can't help but feel compelled to join in. Facebook's most voyeuristic feature is the News Feed, which blasts a notification on to your home page for most anything your friends do (N'Gai's relationship status has changed to "it's complicated" … N'Gai is now friends with Steve Case … N'Gai has joined the Another-Technology-Columnist-Writing-About-Facebook group). I was hooked.

Over the holidays, however, I came across a site that made me wonder whether I should have stayed away from Facebook. The site in question is Spokeo (spokeo.com), which promises that it "finds your friends' blogs and photos that you never knew about, guaranteed" and "tracks your friends' new content, so you don't have to visit their Websites one by one." What this means is that when you sign up for Spokeo, it uses the addresses from your Web-based e-mail accounts to create a list of "friends"—which, in practice, is just about anyone you've e-mailed. Then it proceeds to scan 36 popular sites with social features, pulling together everything your friends have posted into a single, easy-to-read format. All tidbits are fair game: LiveJournal blog posts, YouTube videos, even Amazon wish lists. Most disturbingly, Spokeo never notifies your contacts that you're watching them.

Shortly after joining, I found a colleague's list of Pandora personal radio stations. While most of the titles were innocuous, one in particular, "I Just Don't Think I'll Ever Get Over You," seemed rather, well, personal. I could have found this information using a search engine like Google, but I would have had to know what I was looking for, and would probably have had to sift through dozens of Web pages. I messaged a few friends about Spokeo, and within a day or two they all wrote back to share what they'd dug up about friends and family—and to express their unease about the service.

Spokeo president Harrison Tang, 25, who along with his three cofounders graduated from Stanford University in 2004, says that services like his help users keep up with the proliferation of social networks. But even allowing for a generation gap in how people approach online identity and privacy (younger folks are, after all, less inhibited when it comes to online exhibitionism), many users don't think of sites like Flickr (for your photos) and Pandora (a personalized Web radio station) as social networks that can be mined. If users have no expectation that their activities on these sites will be tracked, doesn't Spokeo represent an implicit violation of their privacy?

I put that question to Tang, who defended himself by arguing, correctly, that Spokeo aggregates only information that's publicly available. "Whenever someone makes their photos or data private, Spokeo will automatically detect that and stop syndicating that content," he says. "I think most social networks have done a good job educating their users on their content privacy. However, if someone wasn't clear about it, Spokeo can actually serve as a tool that allows them to double-check their online privacy."

Marc Rotenberg, executive director of the Electronic Privacy Information Center, agrees that sites like Spokeo can be a useful way for people to determine how much of their dirty laundry is being aired. But when asked what advice he would give Internet users in a post-Spokeo world, he says, "This is one more example of how services that ask people to share secrets with their friends end up broadcasting their profiles to the world." Little Brother, it seems, is watching.

© 2008