
Like all things Facebook
The only winning move... is not to play.
Mass harvesting of private friend lists is a feature, not a bug, according to Facebook which has rejected a bug report detailing a purported breach in site privacy. The social network giant rejected a report by security researcher Shay Priel which demonstrated how attackers could use the 'mutual friends' function to view …
Mass harvesting of private friend lists is indeed a design feature - tit's the whole point of FB apps.
FB apps are there to lure you into accepting T&Cs that legalise Facebook doing an end run about privacy laws and slurp your friend's data. Data Protection laws have a massive hole in that they only compel a data collector to be honest about what they are going to do with your data when they get that data from you directly, not via a friend. By getting it from your friends they don't even have to tell you that they now have your email address, phone numbers and inside leg measurement.
It's one of many clever cons FB plays on people to mine data without people being aware of it.