Last week Facebook officially rolled out its new feature, Graph Search, to everyone on the social network. The new search engine is deemed the “third pillar” of the platform, the other two being Timeline and News Feed, Graph Search draws from the vast information posted by the network’s billion users, allowing users to explore the literally trillions of connections therein.

The feature uses a “social graph” to map the various connections between each user. The new software allows users to perform highly specific searches, enabling them to find, for example “friends from college who like Game of Thrones,” or  “friends who live in my city who like bike riding.” Graph Search is also designed to help people make new connections, from friends of friends who live in L.A., to high school debaters applying to college.

Understandably, the privacy concerns arising from Graph Search are enormous. While the search engine doesn’t make any new or already private information public, it probes deeply into all the information you’ve ever posted on Facebook, making it more prominent and available than ever before. It also pulls from anything anyone else may have ever posted about you, from photos your friends have tagged you in to status updates that mention you – anything that has your name on it. And other than making your profile completely private (or deleting entirely), there’s no way to opt out.

As a result, you may want to do a few test runs to see what Graph Search will turn up about you. Look at your own posts, posts you’re tagged in, displayed photos, embarrassing photos you hid from your timeline, comments, everything. Then untag or delete whatever you need to. Pay attention to likes too – if you once gave a thumbs up to an inappropriate joke, or revealed an embarrassing musical taste, Graph Search will find it. Do you want to turn up in a search for “high school students who like Raffi and the Insane Clown Posse? No, you do not, especially if the person searching happens to be an admissions officer at the college of your dreams.