Sophos researchers studied 200 user profiles in the London Facebook network and found out that 75% of them could be viewed by all the members, friends or complete strangers. What’s worse is that if a user joins a new network, then his or her profile is automatically opened to every other member of the network, although the user had previously set his privacy settings otherwise:

"I was flabbergasted when I joined a network on Facebook using a profile which I thought was secure, only to find Facebook had changed a number of settings and was opening me up to millions of strangers," said Graham Cluley, senior technology consultant at Sophos. "Who was to say that cybercriminals weren’t in that network too? Is it right that Facebook works this way?

Facebook has ultimately put these privacy options in place to protect its flock so perhaps it’s time for the networking phenomenon to take the next step and change its default settings so that when members join a network, they have to actively click to leave their details on show, rather than automatically letting it all hang out online," he added.

The research also showed that 54% of users in the London network show their full date of birth, while 25% revealed information relating to their work. Needless to say, such details might prove very useful to cybercriminals trying to commit ID theft.