Multiple employees were fired for accessing private data in the past. I suspect that it is a serious taboo at the company now to even joke about it.
Given they have 2000+ employees this is just a process that is looking to be constantly abused. I surely don't expect people aren't talking about it, but I'm nearly as confident that it is happening in a way that most people aren't aware of. No evidence, but again, I've seen people do worse, with less access.
I'm gathering that this will never change.
Otherwise we might get to know each other, and become friends, and I'd never be sure that they weren't looking me up. My strategy for avoiding the prying eyes of facebook engineers is to be personally uninteresting to any facebook engineers.
This might not work so well if I were a chick.