An investigation carried out by the Wall Street Journal has discovered that many of the most popular Facebook applications are being used to mine user data by advertisers and online tracking companies.
The report says that a significant number of add ons to the social notworking site have been transmitting identifiying information including freind's names and the unique identifying code allocated to each account to "dozens" of companies.
No stranger to security cock-ups, the latest Facebook issue affects millions of people, breaks the company's own security rules, and cannot be shut down by the user, even if they turn the web site's notoriously unfathomable privacy settings up to eleven.
At least one company, data gathering ouitfit Rapleaf, has mined the information and plans to sell it on as part of a commercial database.
So it looks like Facebook apps are not only incredibly irritating, they can also be ponentially harmful.
Facebook is saying it didn't do it on purpose and is working to plug the holes.