Sometimes the "friends only" preference setting isn't enough for your desired level of privacy for certain information. Facebook has three additional features to deal with this issue and enhance your privacy settings.
First, Facebook lets you restrict certain content to subsets of your Friends by using custom Friends lists. For example, you might have hundreds of friends you don't mind seeing your profile, but only a dozen or so close friends you want to share family photos with. You can create and manage these lists on your Friends management page (Account> Edit Friends) while you're signed in to Facebook. You're the only one who can see the titles and users in your custom lists.
You can use these custom Friends lists in your privacy settings, too. To do this, select "Customize" when selecting a privacy level for sharing that content. Then, use the name of your custom Friends lists as you would individual user names to show or hide that content. See our article How to Artfully Cull Your Facebook Friends List for more about creating, editing and using these lists.
Your second option for enhanced privacy is to use the lock menu when posting specific content. For example, suppose you have posts set to "everyone" in your privacy settings, but you want to post a question for only your "friends" to answer. Each time you make a post or create a photo album, you can use the lock icon to select who can see that post. This allows you to override your privacy settings for that one post. The lock icon menu works the same as the drop-down menus you used when selecting your overall privacy settings.
The third enhanced privacy option in Facebook is block lists. This lets you don an invisibility cloak when certain users try to find you on Facebook. Likewise, it makes those users equally invisible to you. You can add people to your block list by name or by e-mail address. You can also block app and event invites from specific Friends, too, without blocking them altogether. To manage block lists, click Account > Privacy Settings and then click the "edit your lists" link under the "block lists" section of your privacy settings.
If you block a user, there are some important details you should know about how Facebook handles the block. One is that you have the option to tell Facebook why you're blocking the user. This could be useful if you need to alert Facebook to a user's behavior. Also, when you start the block, Facebook immediately removes the user from your Friends list. If you remove a name or e-mail address from your block list, you'll have to add the user as a Friend if you want to reconnect, and Facebook will prevent you from adding that same name or address back to the list for 48 hours.
Now that you have your content sharing under control, let's shift to your privacy settings for user searches, Facebook apps and third-party Web sites.