Seems like Jim Gamble, the head of CEOP is pushing ever harder for this to be implemented.
Funny that, it'll create loads of extra work for CEOP meaning he needs more staff and further justification for his own existence.
I don't even have Facebook, but I'd LOVE for this to be implemented. It'd generate tens of thousands of panic reports a week, maybe even a day - CEOP and the Police would be so swamped, it'd end up being removed after a few weeks.
Sadly, Facebook knows this, so they wont implement it.