It's tempting to see Diaspora* as an evolutionary step in social networking—the BitTorrent to Facebook's Napster—but I doubt it will ever take off. First, it's too complicated. If people are flummoxed by Facebook's privacy controls—if, indeed, lots of Facebook members don't even understand the address bar on a Web browser and get to the site mainly by searching for "Facebook" in Google —how can we expect them to maintain their own private repository of information? Sure, some people will do that, but the most valuable social network will always be the one with the most people. How valuable will Diaspora* be if it attracts only sysadmins?
The larger difficulty in building a privacy-respecting social network is that such a thing is close to an oxymoron. People want to share stuff. Not only that, they want to share stuff without any hassles. Facebook has been far from perfect on privacy, and I'm sure that dollar signs have a lot to do with its woeful record. But Facebook is looking at other numbers, too. Its own growth rate proves that people care much less about privacy than the anti-Facebook crowd seems to believe.
"People have really gotten comfortable not only sharing more information and different kinds, but more openly and with more people," Zuckerberg said earlier this year. "That social norm is just something that has evolved over time." He's absolutely right. Last week, gadget blogger Peter Rojas announced that he's quitting Facebook because he was "tired of not having real control over what I'm sharing." Where did he announce this? On Twitter, a social network that is growing meteorically—and whose privacy controls amount to a single opt-in checkbox. Also consider the rise of sites like Foursquare, where people publish a history of their physical location to everyone they know.
While Zuckerberg is spot-on when it comes to the Web's macro, share-more trends, he's gotten all of the little things wrong. Facebook could and should do a lot better on privacy. In particular, I'd urge it to introduce preset privacy levels. You should be able to go to your privacy settings and see one big dial that lets you choose one of five levels between "private" and "public." This setting would govern your entire profile; the more public you set the dial, the more you'll share with more people. By default, the dial would be somewhere in the middle, but you'd be able to shift it up or down at any time. You'd still be able to adjust more specific controls—you could set your profile to "public" but allow only close friends to see pictures of your kid—but few of us would ever need to.
I hope Facebook makes these changes and recognizes the importance of giving its users permanent control over their profiles. Still, I don't think any privacy tweaks will stem the trend of people wanting to share their personal information on the Web. We're all pushing the dial toward "public" whether Facebook pushes us there or not.