[ErrantX]

Not much more than they are already. There isn't an awful lot you can do to prevent this happening because there are too many variables.

> It seems to me that a paedophile using Facebook to contact kids will be very visible with certain statistical analysis of user behavior

I'm cautious of such methods - they aren't infallible, and what do you do with the results? Read their messages to be sure? Contact the police? Put a warning on their profile that others can see? All of that feels worrisome.

Really your kid being talked to by a pedophile is reasonably low probability. The chance of them being coerced into sending a photo or meeting them is also fairly low (for the most part those who use chat in this way aren't particularly predatory - they are more ill, or lonely and mislead. Not that this excuses them ofc).

Ultimately education of parent and kids seems the best solution.