If you use Facebook and care about your privacy, take a moment to read this blog entry. Facebook has made some major changes that may allow a great deal more people to see your personal photos and videos, date of birth, family relationships, and other sensitive information.

While logged in to Facebook, click the "Settings" link and you should see a box that looks like the one pictured below. You may see that Facebook has reset your privacy settings, so that the everyone can now see the information on your "About Me" page, as well as your "Family and Relationships" data; "Work and Education"; and most importantly "Posts I Create," which includes status updates, links, photos, videos and notes. Below is a screen shot of what my privacy settings looked like when I recently logged in.

The new privacy settings instituted across the Facebook network may also expose your birthday, religious and political views, and "photos and videos of me" to your "Friends of friends," meaning that any one of your friend's friends can now view this information.

This "Friends of friends" setting may be perhaps the most important, as it has the potential to dramatically expand the number of people who now have access to this data.

If you do not wish to accept these new privacy settings, change all or some of the relevant radio buttons to the "Old Settings" selection, and then click the "Save Settings" button at the bottom of the page.

The changes may have even caught Facebook.com Chief Executive Mark Zuckerberg by surprise: Valleywag features a story Friday noting that the new privacy settings exposed a cache of more than 290 photos of Zuckerberg that were uploaded by people who had tagged him in their pictures but that were previously hidden (the photos don't appear to be accessible at the moment).

Sophos' Graham Cluley has published a short video explaining in a bit more detail what these privacy changes mean. For example, Cluley examines Facebook's privacy policy, and finds a rather interesting explanation of what Facebook means when it says "everyone". For example (my emphasis added in the direct quote from the privacy policy, below:

"Information set to 'everyone' is publicly available information, may be accessed by everyone on the Internet (including people not logged into Facebook), is subject to indexing by third party search engines, may be associated with you outside of Facebook (such as when you visit other sites on the internet), and may be imported and exported by us and others without privacy limitations."

"The default privacy setting for certain types of information you post on Facebook is set to 'everyone.' You can review and change the default settings in your privacy settings. If you delete 'everyone' content that you posted on Facebook, we will remove it from your Facebook profile, but have no control over its use outside of Facebook."

Judging from the user comments posted to the Facebook Site Governance page, these changes have not been well received by the Facebook community overall.

Update, 1:54 p.m. ET: Added link to Sophos video and additional information about Facebook's privacy policy.