I don't use it now, but I have done, so yes, I think I know how it works. And the idea that these could unwittingly provide clues for predatory paedophiles to track down children to their homes would be contemptible were it not so pitiable.
In actuality it's both.
My initial point was not about paedophiles but about over--sharing with the general public, as opposed to family, and identifying yourself and your child in the process, in an intimate and vulnerable moment in their life.
I also agree with Brownie about invading a child's privacy - there is a difference between seeing kids running around or doing stuff they would openly do in a public setting and taking a private moment and putting it out for public consumption with your name attached for no discernible reason other than you like to draw attention to yourself using whatever props available.
In relation to paedophiles - there is a lot of on-line grooming that starts of with innocent questions about innocuous things based on clues picked up from posts and pictures and once trust has been gained over a long period of time and many on-line chats the child is subtly manipulated to reveal more and more about themselves in order to gain influence and control - "I see from your photo you like football, what team do you support?....oh same here....why don't we put our team shirts on and chat, I bet you look like <insert football hero here>in that shirt....Why don't you put the webcam on and show me....you look like you're really strong - you have wide shoulders for a kid your age...bet you can do lots of press ups...do you have a six pack...etc etc
Why would a paedophile waste their energy following a random kid home when contact on-line is easier, more subtle and a lot easier to gain the child's trust? The paedophile can pick and choose their target on-line from photos and there is a huge nationwide selection of kids compared to the handful of kids that show up to their local park - especially true since kids seem to spend less time playing outside these days. The paedophile would organise a meet-up only once they had groomed the child sufficiently and it would be at a time and place convenient for the paedophile.
Since there are so many photos shared on-line with millions of people every day there are so many opportunities for someone to catch a paedophile's attention and so much time plus zoom in technology to pore over photos and pick up information to use to groom someone, if you are clever, manipulative and that way inclined.