Facebook is making big changes to its privacy settings that may mean millions of people begin to expose information that they previously considered to be restricted to only their Facebook friends to the entire internet.

This YouTube video explains more.

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Facebook is recommending that users adopt a series of new privacy settings that would reveal their personal data to anyone on the internet. Chances are that when you login to Facebook today you'll be advised to make various pieces of your personal information available for "Everyone" to see.

To get a clear picture of what Facebook means by everyone (and its implications) you should check out the revised Facebook privacy policy:

"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."

So, let's make this clear. If you make your information available to "everyone", it actually means "everyone, forever". Because even if you change your mind, it's too late - and although Facebook say they will remove it from your profile they will have no control about how it is used outside of Facebook.

There's a real danger that people will go along with Facebook's recommendations without considering carefully the possible consequences.

If you're interested in being safer on Facebook, read more about the security and privacy challenges that exist for Facebook users. You could also do a lot worse than follow the advice in our step-by-step guide for better security and privacy on Facebook.

And, if you're a regular user of Facebook, be sure to join the Sophos page on Facebook to be kept informed of the latest security threats.