Something similar happened in our family. Then someone sent the link to grandma and grandpa. Also, a potential employer happened across it. The pictures may still be out there but at least now they can only be viewed by those “invited” to see their pages as it has since been changed to a “private” setting. I know this doesn’t address that main point of your rant, but at least it did help get them to stop advertising for the entire world to see. It’s a start. A little shame can go a long way.
The colleges do a great job trying to get this message across to the kids about how once it’s in cyberspace... and employers do check but even when they are private, they are not so private because the kids often have hundreds and hundreds of friends who can all see the stuff.