Facebook unveiled Graph Search today. Many are probably wondering what this means for privacy. Facebook has already put out a video discussing that very issue.
"With Graph Search, you can look up anything shared with you on Facebook, and others can find stuff you've shared with them, including content set to Public," says Facebook. "That means different people see different results."
"I speak Spanish, and I only share that info with my friends," says Julia from Facebook's search team, in the video. "That means that if anyone who is not my friend searches for 'people who speak Spanish' I won't appear in the search results they see."
Basically, people won't be seeing anything in Graph Search that they don't already have access too, so this shouldn't be much of a concern. That said, if it's been a while since you took a look at your privacy settings, it might not be a bad idea to revisit them just to make sure you're not sharing anything you don't want to be with anyone you don't want to be sharing with.
You can also go to the "about" section of your timeline, and edit who can see various aspects of your profile. You can go to the activity log to manage your overall activity on the social network, including what you've shared, like photos, or tags of you. You can look at all the photos that you're tagged in, for example, then see which are hidden or visible on your timeline.