Taggart 
It was my job for a decade to try to keep tweens and teens safe online. Let me tell you what you already know: no law or technology can do it. There are no lengths kids won't go to to talk to friends without prying eyes. The harder you try to lock it down, the dodgier their solutions will be.
stonedonkey 🕹️🎮👾@mttaggart IRC is still a thing.. message boards can be self hosted... Hell listserv still works ... There's a myriad of work arounds that they'll migrate too it just takes is a nudge.
Personally I hate some of these walled gardens and maybe it's for the best.