Facebook needs to make money and so far it seems that the most likely route to riches for the Internet darling will be your personal information. The company recently (December 2009) unveiled a radically revamped set of privacy controls which are better than previous efforts, but make one very important change -- by default almost all of your data is now made public.

For accounts created since the change, most profile settings, contact information and application settings in Facebook default to "everyone," which means the whole world can see everything you post. For more details on the good bad and ugly of Facebook's most recently privacy changes, see the [http://www.eff.org/deeplinks/2009/12/facebooks-new-privacy-changes-good-bad-and-ugly Electronic Frontier Foundations overview].

But the worst part for most people will be the public search results settings which means if you post something and later decide you want to switch to a private profile, well, good luck trying to remove your embarrassing posts from search engine indexes.

The good news is that Facebook actually offers pretty fine-grained control over which bits of personal information you share. The bad news is that the high level of control makes preserving your privacy a fairly complex process. There's no longer a simple check box that says make my profile private. 

But fear not, we've got you covered with this how to.

== Locking Down Your Profile ==

The First step is to head to your privacy settings under the account menu at the upper right corner of your Facebook page.

On the privacy page you'll see five categories of privacy settings: Profile, Contact Information, Applications and Websites, Search and Block List.

Start at the top with Profile information and change all the options to "friends" this will stop people you don't know from accessing any of your personal data.

Do the same for contacts, most of which, thankfully, still defaults to Only Friends.

Also be aware that each setting has a "customize" option which allows you to, for example, set your information to visible only to friends but also block certain "friends" like your mom so she won't see your drunken late night wall rants.

== Applications and Outside data ==

Facebook isn't just Facebook anymore, it includes a vast network of connected websites and applications linked together through Facebook Connect and Facebook's App Platform. 

This is one area that many people overlook, but it has perhaps the highest potential to unwittingly leak information about you.

Head to  Privacy Settings >> Applications and Websites and adjust the settings to Friends Only. 

But there's more. Click the edit settings button for the "What your friends can share about you" section and uncheck anything you aren't comfortable leaking out of Facebook.

Finally, and in the long run, most importantly, head to the Search section of your Privacy settings and uncheck the box that allows search engines to index your posts.

== Conclusion ==

It takes a little bit of work to lock your data down, but if you'd like to keep Facebook the private, for-your-eyes-only social network it once was, you still can. At least for now.