Are you a member of a geographic network on Facebook?
We've raised the privacy challenges on Facebook, and specifically the issue of geographic networks you might have joined, before - and now rock star Bono of U2 has had private photos exposed to the media because of it.
Check out the video we have made for more information:
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The 48-year-old Cuban-heeled crooner and anti-poverty campaigner was revealed to have been up to hijinks in St Tropez with a couple of bikini-clad girls after they posted their private photos to the social networking site.
The only problem was that American fashion student Andrea Feick was a member of the New York geographic network on Facebook, meaning that her profile was open for over a million people to view. Of course, this could all be very innocent and the girls could be family friends - but that didn't stop the newspapers making hay about what Bono might be up to away from his wife Ali.
Facebook is made up of thousands of networks worldwide, and users are encouraged to join them in order to meet and make friends with people in their area.
Even if you have previously set up your privacy settings to ensure that only friends can view your personal information and photos, joining a geographic network (such as New York or London) automatically opens your profile to every other member of the network.
Facebook automatically changes your privacy settings when you join a geographic network - potentially opening up your private information to identity thieves - so you have to be careful to reset your security on the site to keep strangers away from your holiday snaps. Facebook's privacy features are more
sophisticated than some competing social networking sites, but the fact that it changes these without asking when you join a geographic network is not good at all.
Last year, Sophos research revealed that 75 percent of the London network, the largest geographic network on the site, were allowing their profiles to be viewed by any other member of the network. Worryingly, 54 percent were revealing their full date of birth - vital information for hackers wishing to commit identity fraud.