The scope of the things we already do to "protect the children" is tremendous. None of them have, will, or could prevent them from continuing to use it as an excuse for things that should never be done.
You seem to have jumped from "protecting children" to accusing them of an unrelated war crime for not censoring things aggressively enough.
On top of that, the relevant law they would have to comply with in those countries would be the laws of those countries, and those are the governments committing the genocides.