Debates about online privacy often seem to assume relatively homogeneous privacy preferences among Internet users. But the reality is that users vary widely, with many people demonstrating that they just don't care who sees what they do, post or say online. Attitudes vary from application to application, of course, but that's precisely the point: While many reflexively talk about the "importance of privacy" as if a monolith of users held a single opinion, no clear consensus exists for all users, all applications and all situations.

If a picture is worth a thousand words, this picture makes the point brilliantly--showing:

locations where [Flickr] users are more likely to post their photos as "public," which is the default setting, in green. Places where Flickr users are more likely to put privacy controls on their photos show up in red.

Of course, geography is just one dimension across which users may vary in their attitudes about privacy, but the map makes the basic point about variation very well. Seeing what users actually do in real life says a lot more about their preferences than merely polling them about what they think they care about in the abstract--as my colleagues TLF Solveig Singleton and Jim Harper argued brilliantly in their 2001 paper With A Grain of Salt: What Consumer Privacy Surveys Don't Tell Us (SSRN).