Social-networking site Facebook is set to increase its sphere of influence by making people listed in its directory visible in search engines such as Google and Yahoo.

See also: Facebook: the most dangerous site on the web?

Existing users logging in to Facebook learnt of the plans only this week where they were greeted by a pane on their profile home page informing them of the plan to make Facebook profiles public.

Privacy warning

Privacy warning

Privacy concerns have already been raised about the successful social-networking site since it transpired that Facebook users were routinely posting details such as their date of birth, mobile phone number on the site.

Unless users are careful to restrict their profile visibility to their trusted group of friends, posting such details means Facebook users are leaving themselves ripe for exploitation by identity thieves.

Along with information such as where you live, your occupation and other details that make you personally in identifiable, a data thief could very easily pose as you for the purposes of credit card applications and other exploits.

Such risks with Facebook have been highlighted in the media (by PC Advisor, among others) but many users continue to display detailed contact and personal information. This advice is even more important now that Facebook is going public.

According to the message from Facebook, the public search listing will begin in a few weeks' time, giving users a couple of weeks to edit any content and alter any settings they don't want the world to be able to find.

A statement on the About pages of Facebook this week reads: "Starting today, we are making limited public search listings available to people who are not logged in to Facebook… The public search listing contains less information than someone could find right away after signing up anyway, so we're not exposing any new information and you have complete control over your public search listing."

While there are indeed tools to limit the amount of information others can see about you on the Facebook site, the default settings allow anyone to view information about anyone in their extended network – in other words, details of friends of friends of friends.

Even so, anyone logging in to their Facebook profile today will see preferences for newsfeeds and other events, where they can choose to display more of less information about themselves.

Find out how to secure your Facebook profile on page 2 >>