Moderation of the kind you're talking about is a full time job and an industry. Yahoo once had a thriving chatroom service, but they couldn't stop minors from using it (or adults from talking to minors) and they took it down. The entire service. They were years ahead of other social media services in that department and they just tanked it because they didn't want the risk.

If a billion dollar company can't stop this from happening, I wouldn't invest too much grief in making this place controlled.

I would only focus on reporting people who are actually trying to commit a crime against children. Grooming and other sleaziness. The atmosphere should be vigilant against actual pedos coming here to find targets.