The Failures of Facebook

I was reading a few articles about Facebook's latest privacy scandal recently.
Apparently, the Facebook developers were trying to "improve" the privacy features - on Facebook, one can preview how someone else would see one's own profile. However, in doing so, they managed to allow (by accident, of course) anyone to see what any of their friends are doing on Facebook at that moment (including the ability to essentially spy on other people's chats).
This is not the first time Facebook has messed up privacy-wise (Facebook is constantly revising privacy options in the hopes of making them better, while in reality, every change creates a progressively larger backlash). However, this one really takes the cake in terms of how big a goof-up it was.
Seriously, Facebook?
Can they get any change to the interface right?
I am really starting to doubt the Facebook developers' abilities right now (though that's not to say that I didn't before either).