Here's a good way for Facebook to keep its demographic young: IT security firm Sophos reports that early on during Facebook's beta test of a new user-profile design, the site revealed its members birth dates, even if members had set that information to private. That'll keep the Olds who turn 43 every year off the site. Facebook needs to be very careful when it comes to privacy — the site would like to figure out a way to target ads based on user's personal data, and wants to make sure users are comfortable inputting accurate information. And Facebook is being hypocritical: When Slide's Facebook Top Friends app revealed users' birth dates, Facebook temporarily kicked the app off the website. Of course, we won't hold our breath waiting for Facebook to suspend its entire website. But maybe it could back down from its holier-than-thou pose that the platform is a level playing field and Facebook is just another player? Yes, please.