How to protect your kids from online sexual predators:
LISTEN TO YOUR KIDS, YOU IDIOT.
Also, take an interest in your kids' online social lives. Look, if your kid can't be stopped from wanting to pretend they are a winged fox or something without also utterly alienating them and losing their trust, then make your own fursona, and try to learn something about their community, its leaders, its issues, and its dangers. Be involved, lead, and genuinely care.
This is not complicated.