Facebook began as a place for college connections, secluded from the prying eyes of the outside world, but today that era is officially over. Major Facebook investor Microsoft announced this afternoon at the Web 2.0 Summit that it has closed deals to bring status messages from both Twitter and Facebook into the search results of Bing.com. Twitter search is live now, Facebook is forthcoming.

Facebook is opening up to a search engine - that's very big news. Only content from accounts marked public will be indexed by Bing, but it's a sea change none the less. Facebook has an explicit, acknowledged agenda to make more people comfortable sharing more information publicly - once they do, that information will be searchable on Bing. This 'aint your big sister's Facebook anymore.

Facebook opened on-site search across user profiles and messages late this summer. The company has been careful to only expose information from people who have opted-out of their own default privacy settings and we don't expect this Bing deal to be any different. While some people like Facebook because of the privacy settings, a growing number of users like it for the promotional and networking advantages that can be maximized with a public profile.

You don't want to be public with your Facebooking? Facebook will respect that, but the company does hope you'll change your mind. Seeing some peoples' Facebook status messages show up in Bing search is likely to freak out people who aren't familiar with public profiles and have a strong interest in their own data remaining private.

It's very unlikely that Bing will be allowed to cache the Facebook messages it serves up.
Facebook status messages used to be entirely closed to outside search engines - and now they will not be. Even these public search results won't be full participants in the open web, though. It's very unlikely that Bing will be allowed to cache the Facebook messages it serves up. Facebook prohibits other software from keeping user data in cache because the company says users must be allowed to change privacy settings and have those reflected everywhere around the web that Facebook data could be found. That's an unusual arrangement for a search engine. It breaks one of the fundamental laws of the internet - that what you publish publicly once is public forever.

Will the company make a similar deal with Google? Probably not. Twitter may have gone both ways, but Facebook's long-term ambition to challenge Google and its Microsoft backing will probably mean that the world's leading search engine will never be allowed to index activity on the world's leading social network. The public parts of profiles, yes, but activity? No.

Say hello to the new Facebook, now a partial player in one public part of the rest of the web.