To look past the "give up" post, it did have a good point about how children will get into contact with such feed monsters.

I think it will be a good idea to try and get other parents on board. Other parents of the kid's classmates. Maybe they are struggling with this too, but don't see the way forward. And you can show them the content of feeds and shit that kids consume. You can come up with some minimum age or other idea, which you suggest for children to have, before you as a group of parents allow them to access things. Or you can come up with a once a month special lesson or something, where you show what can go wrong to the kids, and cooperate with the school.