Media claims about the incoming head of MI6 show the need for knowledge on privacy settings on social networking sites.

The Mail on Sunday claimed that the wife of Sir John Sawers left her privacy settings on the social networking website wide open for anyone in the ‘London' network to view her updates. This allowed details of Sir John and his family to be viewed by any of the almost four million people who are members of the 'London' geographic network.

The profile included personal photographs of them partying and on holiday, the location of their flat, and the identities of friends and close associates. The paper speculated that Sawers could be in breach of MI6 guidelines after it was revealed that one relative on the network posted a message of congratulations when his appointment was announced.

According to Sophos senior technology consultant, Graham Cluley, the issue here is Facebook users joining geographic networks and not properly checking their privacy settings afterwards.

Cluley said: “When Sophos investigated this problem before, we found that a staggering 75 per cent of people in Facebook allow their profiles to be viewed by any other member, regardless of whether or not they have agreed to be friends.

“Hopefully revisions Facebook has made since we did that privacy test has increased awareness amongst users that they need to take more care over who they share their personal information with - but we are still finding people who are leaving themselves wide open to potential identity theft by sharing data with complete strangers.”

Cluley further claimed that Lady Shelley Sawers seemed to have learnt from the experience, as all traces of her account on Facebook have disappeared following the newspaper investigation.