I would say that most users of these kind of applications do not even dream of the consequences of the combination of the data the make available. It needs geek mentality and more algorithmic thinking then you would expect to realize this.
You could even try to reconstruct foursquare locations of people who are not on FS just by their FB buddies ... try to explain that to "normal people".
And isn't it a bit scary that you seem to need more and more caution as time goes by? Would we need more responsibility on the side of the makers or do we keep blaming "normal people" for the world we create? (like we do it with, let's say, their inability to maintain secure passwords?)
You could even try to reconstruct foursquare locations of people who are not on FS just by their FB buddies ... try to explain that to "normal people".
And isn't it a bit scary that you seem to need more and more caution as time goes by? Would we need more responsibility on the side of the makers or do we keep blaming "normal people" for the world we create? (like we do it with, let's say, their inability to maintain secure passwords?)