There's basic things a parent has to do because there will always be bad actors going after your kids. Also, you have to pick a good school.

Welcome to the Internet; clearly this is your first day on it. We're in a world where there's no possible way to 100% stop it anymore. You can't watch your kids 24/7, and the second you pass out trying your kids are going to be at risk. No matter how much you mete out and filter your kids' internet, no matter how much you make the kid mistrust anyone who's not directly in your family and look side-eyed at the other family members, SOMEONE is going to get through. And if you do all those things, your kid's going to lash out hard and more of them will get through.

They don't see themselves as groomers, that's the issue. They think they're the good guys.

I agree. WHICH IS WHY THEY HAVE TO BE THE ONES THAT ARE ALLOWED TO BE SUED OVER THIS STUFF. These groomers do truly believe they're the good guys, and no matter what happens to the former victim or the people who their scripting forced to give the former victim their way, they're not going to stop until you can punish them for it. The only way to stop them is to punish the groomers for this and make it so they are liable for these things. Inevitably, the groomers will cry and say they're really the good guys and the world is oppressing them because they're Dark Triad POSes and that's what they do, but if they can't afford the Internet because their money's all going to their victims, you take them out of the picture.