Someone can intercept your banking information across the radio waves.
I think the parents are now saying, ok, there's a problem, now we need to know what to do to fix it.
The idea of the status - 'I have more friends than you' - seems to be important to the kids. But you don't know who these people are.
But as soon as you list that person as a 'friend' or put them on your friends list on that particular site, they now have access to that information.