Once a stronghold of privacy, Facebook has started playing fast & loose with users’ personal data in recent months. If you’re scratching your head wondering how all of this affects you as a user of the service, read on.

The more the Internet becomes a part of all our lives, the more our privacy seems to be taken for granted. Search giant Google has been criticized at every turn for having “loose morals” when it comes to their users’ personal data, but they’re quickly being upstaged by the wildly popular social networking site Facebook -- formerly a privacy “fortress of solitude,” but that’s changed in recent months.

While Facebook used to assume that you didn’t want to share much personal data with the world outside of their walled garden, the service now seems to be taking a fairly casual (some would say irresponsible) stance on the issue, with recent changes exposing more information about you to the outside world than ever before. (Facebook has a full “guide to privacy” on their website.)

The effect is two-fold: The privacy options are now so labyrinthine that many users just ignore the problem or cross their fingers and hope for the best, but users who take a little time to arm themselves with information about the changes find that they have more granular control over their privacy than ever before.

Journey with us now, MacLife.com readers, as we take you on a wild and crazy ride through all of Facebook’s privacy settings and decipher what all of those options mean for you--and your personal data.

First Things First: My Account

Thankfully, managing your privacy is literally only a click or two away. From any Facebook page, find the Account tab in the upper-right corner; click it and you’ll find Privacy Settings in the submenu. However, before you venture into that thick jungle of options, let’s first visit Account Settings under the same menu.

At the top of the My Account page, you’ll find seven tabs. The one we’re interested in is the last one on the right side: Facebook Ads. These newly-added settings are among the most potentially sinister that Facebook has enacted, since they control how advertising using your data is displayed on the site to your friends--and someday, even to third parties.

The Facebook Ads settings include two controls, and currently they either allow ads to be displayed to friends with your information, or to no one at all. The first setting controls ads displayed by third parties; Facebook is quick to note that they do not give such applications or ad networks the right to use your name or photo(s) in ads, but that could change in the future. If the mere idea of that sends a chill down your spine (as well it should), change the “Allow ads on platform pages to show my information to” setting from “Only my friends” (which is the default) to “No one.”

Likewise, the setting at the bottom of this page controls how your information is used in Facebook-generated ads. As you can see from the two sample ads on the settings page above, by default Facebook can use your personal tastes to help sway your friends into also becoming fans of things that you like. If you find this somewhat nefarious and would prefer to opt out of the practice, change the “Show my social actions in Facebook Ads to” setting to “No one.” Now your friends will have to decide for themselves what’s hip and cool.

Be sure to hit the “Save Changes” after each choice, otherwise your new options won’t take effect.

Next page: So Many Privacy Settings, So Little Time