Facebook's timeline security settings may not be set the way you'd expect

If Facebook dragged you kicking and screaming into the new timeline feature, be aware that your old privacy settings won’t carry over. I would recommend that if you are concerned about your Facebook content becoming public knowledge, you might want to check this.

Click Privacy Settings. Scroll down to Limit the Audience for Past Posts, and click Manage Past Post Visibility. You’ll then get the pictured ominous warning box.

Click Limit Old Posts. As the warning box says, there’s a chance that friends of friends you’ve tagged (in pictures etc.) can still see your stuff, so you may have to go individually to each of those posts and change the audience setting. That could be pretty time consuming, especially  if you’ve been on Facebook for years and/or post your every single thought or activity. You decide if it's worth the extra effort.