Even when I paint the worst possible scenario in my mind (I get killed because of my Facebook data) it's still not something I can be bothered about. I could just as well be hit by a car tomorrow but I don't worry about that.
Of course. The problem is that look both ways in this case basically means stop using Facebook. It's not something I'm willing to do, regardless of risks. It's an important part of my life.
In your case, I wouldn't worry about the risks of FB as much as about the fact that you seem to keep going back and forth in your thoughts. You just asked us, a few levels up, to consider the "What-if?" scenario of some future Hitler coming to power, with all your data available on FB. And so people started explaining to you that, yes, in that case, you'd definitely be very naive not to consider the (obvious) risks of having all your data up on FB.
To which your answer to that was, basically, "But that's not very likely to happen."