There are dozens of valid answers to this question. Some are probably quite funny. The one that interests me at the moment: a chief privacy officer.

Microsoft has one, Peter Cullen. Google and Yahoo don't.

Google said yesterday it wanted to be more transparent. It would also do well to be more accountable. Hiring a chief privacy officer would demonstrate that commitment.

In a recent open letter to Google, privacy advocate Lauren Weinstein argues that Google should create a team dedicated to privacy that reports to high-level management.

Apparently, Google has heard this before. Ray Everett-Church, a lawyer with extensive privacy experience, reports having urged Google to hire a chief privacy officer over five years ago. "Unfortunately the folks I spoke to couldn't seem to wrap their minds around the concept of, much less the need for, such an effort," he writes in an E-mail posted to David Farber's Interesting People mailing list.

It seems not much has changed. Google and Yahoo could learn a thing or two from Microsoft.